THE MEDIEVAL POPULATION OF POLOTSK ACCORDING TO THE ANTHROPOLOGICAL DATA

The aim of this study was to analyze human skeletal remains from 13th—14th centuries burials discovered on the territory of the Lower Castle in Polotsk, Belarus. The article deals with the morphological characteristics of medieval urban population and skeletal stress indicators such as mortality and cribra orbitalia. 
According to most craniological characteristics, a series of male skulls from Polotsk of the 13th—14th centuries is similar to a sample of the medieval rural population of Polotsk land from burial mounds of the 11th—13th centuries. The differences relate to an increase in the cranial index in the later Polotsk series, which reflects the onset of epoch-making brachycephalization. In addition, Polotsk urban population differs from the rural population in a number of features characterizing the structural features of the facial skeleton (a higher face, a larger index of facial protrusion, a smaller protrusion of the nose). These differences can be genetically determined and indicate the participation of the alien component in the formation of Polotsk medieval population. 
The body length of adult men from Polotsk varies within 162—175 cm and averages 169.5 cm. The body length of adult women varies within 147—159 cm and averages 156 cm. Compared to the later Polotsk population of 17th—18th centuries, the medieval urban population was taller (2.5 cm in men and 2 cm in women). 
The average age of adult death in the studied group was 35.1 years. The average age of death for Polotsk women was 3 years less than for men. 
The group of Polotsk medieval population is characterized by relatively high frequencies of cribra orbitalia. Among adults, the indicator is present in 32.2 % of cases, among children — in 55.5 % of cases. 
Compared with the rural population of the 11th—13th centuries urban population of Polotsk of the 13th—14th centuries had higher mortality rates and increased incidence of cribra orbitalia, which indicates deterioration in general health in Polotsk urban population. The most probable causes of this phenomenon were, on the one hand, negative factors of urbanization, and on the other hand, the cooling of the climate, which began in Europe in the 14th century and led to deterioration in the living conditions of a significant part of the region’s population.

Introduction. Polotsk (Polack) is one of the oldest city of Belarus and eastern Slavs. The first annalistic mention of Polotsk dates back to 862. In the 9 th century Polotsk was a tribal center of the Polotsk Krivichi. During this period, Polotsk was well known to the Scandinavians under the name Pal(l)teskia, Pallteskioborg. In the 10 th -11 th cen turies, Polotsk became the center of the Principal ity of Polotsk, in which its independent princely dynasty rules. Unlike other Kievan Rus cities, in the 13 th century Polotsk did not experience the invasion of the Mongol-Tatars and Crusaders. At the beginning of the 14 th century Polotsk became part of the Grand Duchy of Lithuania. For a long time Polotsk became an important outpost in the north of the state, with the help of which the great princes of Lithuania spread their influence to neighboring Russian lands, and also fought against the Livonian Order.
Systematic anthropological studies of the an cient population of Polotsk have been carried out since 2005. In the course of many years of archaeological research which are carried out on the basis of Polotsk State University, a rep resentative osteological collection was obtained, including materials from urban burials, dated mainly from the 17 th -18 th centuries. The results of a comprehensive anthropological study of these materials are reflected in a number of publica tions (Емельянчик 2012;Borutskaya, Vasilyev, Yemialyanchyk 2015).
In 2014, as a result of archaeological excava tions at the foreland of the Lower Castle in Pol otsk, which were conducted under the guidance of D. V. Duk and A. L. Kots, for the first time materials on the medieval population of Polotsk dated to the 13 th -14 th centuries were obtained. An anthropological study of these materials al lows us to trace the characteristics of the forma tion of Polotsk population in the Middle Ages, to determine the nature of the relationship between urban and rural populations, to characterize the living conditions and general health status of Pol otsk population in the Middle Ages.
Material and methods. Osteological series of the 13 th -14 th centuries from the territory of the Lower Castle in Polotsk is characterized by a mixed sex and age composition and is repre sented by skeletons of various degrees of conser vation, which belonged to at least 61 individuals, including 12 subadults and 49 adults (24 males, 12 females, the gender of 13 individuals was not determined due to the fragmentary preservation of the skeletons). Subadults' remains make up about 19.7 % of the total number of those buried, which most likely indicates an underestimation of children's burials, due to the worse preserva tion of poorly mineralized children's bones.
Sex and age were determined using standard methods. Sex was determined based on an assess ment of the structural features of the skull and pelvic bones characteristic of men and women. When determining the adult age estimation, the extent of cranial suture closure combined with the degree of tooth wear was taken into account. The age of subadults skeletons was determined based on the degree of dental formation according to the Ubelaker's scheme (Ubelaker 1989, p. 64), the degree of ossification of different parts of the skeleton, as well as on the basis of a morphologi cal criterion that takes into account bone size and maturation (Piontek 1996, p. 143). The sex and age determination results were used for paleo demographic analysis. When constructing life tables, the concept of a conditionally stationary population was used. The average age of death was calculated by multiplying the average of each age class by a fraction of this class. The average of the first age category (15-20 years) was taken equal to 17.5 years; the average of senile age was taken equal to 52.5 years respectively.
Measurement of craniological material with subsequent calculation of angles and indices was carried out using a standard technique (Алексеев, Дебец 1964). To evaluate the obtained indica tors, tables of craniometric constants were used (Алексеев, Дебец 1964, p. 112-127). The recon struction of the intravital body length was carried out on the basis of the measurement data of long bones according to the Trotter and Gleser method (Piontek 1996, p. 180-182).
The severity of cribra orbitalia (porosity and hyperostosis of the superior wall of the orbit) was estimated according to the Nathan and Haas scale: 1) porotic type consisting of isolated small pores on the bone surface; 2) cribrotic type, in which the pores are large and conglomerate, but still preserve their individuality; 3) trabecular type where the apertures have become confluent, and the bone remaining between them has been converted into a network of trabeculae (Nathan, Haas 1966, p. 351). The statistical significance of the intergroup differences in the occurrence of the trait was checked using the χ 2 test.
Research. craniological study. Males. The state of skeletal material preservation allowed the measurement of 18 male skulls (table 1). The total series of male skulls is characterized by mesocrany, large longitudinal and average transverse diameter of skull in combination with high brain case. The face is average -in terms of absolute dimensions and upper facial index, or thognathic, well-profiled in horizontal plane with insignificant flattening at the level of orbits. The orbits are of average breadth and low -in terms of absolute dimensions and orbit index. The nose is characterized by average size of piriform aper ture and high nose bridge.
As for the individual variations in the brain shape, eight out of 17 male skulls are character ized by dolichocrania, eight have a mesocranic form, and one is brachycranic. Inside the male sample, there are skulls with both a narrow and a wide (in by-zygomatic diameter) face. A variation in the height of the face is also observed: 4 skulls have a high and very high face, 5 skulls have a low face, and the rest are medium in height. Ac cording to the upper facial index, 5 skulls belong to the category of narrow-faced, 2 skulls -to the category of broad-faced; the remaining 7 have a face of medium width. According to the face pro file index, most skulls are orthognathic, one is mesognathic, and one of the skulls is character ized by prognathism.
Despite the revealed variability of craniological signs, most of the standard deviations of the sam ple of male skulls are within the standard values (Алексеев, Дебец 1964, p. 123, 124), except for the face base length, the upper facial height and orbit height, the nose breadth and height.
Females. The state of skeletal material pres ervation allowed the measurements of only 7 fe male skulls (table 1). In almost all indicators of the cerebral and facial parts of the skull, as well as in the angles of horizontal profiling, the female sample is similar to the male one. Like the men's, the women's series is characterized by mesocrania with large sizes of the longitudinal and altitudinal diameters of the skull, and me dium -transverse, orthognathic, face average on the upper facial index. As in men, the face is slightly flattened at the level of the orbits, and is strongly profiled at the level of the cheekbones; the nose protrudes well, as evidenced by the high values of the dacrial and symotic indices.
Some differences between the female and male samples relate only to certain size categories. If in the male sample all sizes of the facial skeleton are classified as medium, then in the female sam ple, most of the absolute sizes (malar diameter, upper facial breadth, and upper facial height) be long to the category of large values.
Individual variations of the female sample are presented as follows: of 7 skulls, two are char acterized by dolichocrania, three skulls have a mesocrane shape, and two have a brachicrania shape. According to the upper facial index, one skull belongs to the category of narrow-faced, the remaining three to the category of medium-faced. According to the index of the face protrusion, most skulls are orthognathic, mesognathism is marked on one skull.
The similarity of the signs of the neurocranium and viscerocranium of the skull, as well as signs characterizing the profile of the face and the de gree of protrusion of the nasal bones, allows us to state the anthropological proximity between the female and male samples.
Comparison of a series of male skulls of the 13 th -14 th centuries from Polotsk with a chrono logically close series of rural burial mounds of the 11 th -13 th centuries from the territory of Polotsk Land showed significant similarities in most abso lute sizes (Емельянчик, Шипилло 2018, p. 20-22). The Polotsk series of the 13 th -14 th centuries naturally differs from the rural series of the 11 th -13 th centuries in higher skull index, which reflects the beginning of the epochal process of brachycephalization in the later Polotsk popula tions. In addition, Polotsk series of male skulls is statistically significantly different from the rural series in a higher face, a larger face profile index, as well as a lower nose bridge.
The female series of skulls from Polotsk differs from the mound female series in larger absolute sizes of the brain and facial sections. The com parison of Polotsk female series and the mound series with the use of the Student's t-criterion revealed nonrandom intergroup differences in longitudinal diameter and height diameter of the skull, skull base length and face base length, as well as upper facial breadth. Like the men's, Pol otsk women's series is characterized by a larger skull index compared to the earlier rural series.
The fact that the urban series of male skulls of the 13 th -14 th centuries from Polotsk differs from the mound rural series of the 11 th -13 th centuries from the territory of Polotsk land in a complex of features that are not associated with secular trend and characterizing the structural features of the facial skeleton (a higher face with a smaller protrusion of the nose, a larger face profile index) may indicate genetic differences and participa tion in the formation of alien component in the anthropological composition of the later medieval Polotsk population.
The body length of adult men from Polotsk, reconstructed on the basis of measuring the long tubular bones of the limbs, varies within 162-175 cm and averages 169.5 cm. The body length of adult women varies within 147-159 cm and averages 156 cm. Compared with the later popu lation of Polotsk 17 th -18 th centuries the medie val urban population was taller. So, the height of medieval men was 2.5 cm more than the height of the townspeople of the 17 th -18 th centuries, the medieval Polotsk women were on average 2 cm higher than the women of the 17 th -18 th centu ries. Paleodemographic analysis. For the studied osteological series, a life table was calculated (ta ble 2). Due to the fact that the average life expect ancy at birth is significantly distorted depending on the representativeness of the child part of the sample, the mortality rate of adults was analyzed. The average life expectancy without taking into account child mortality (Е 20 ) in the group of the Polotsk medieval population was 16.2 years. This means that individuals who have reached the age of 20, on average, could expect to live another 16.2 years. The average age of adult death in the studied group was 35.1 years. The life expectancy of Polotsk women of the 13 th -14 th centuries was 3 years less than that of men.
The average life expectancy and the average age of death of Polotsk 13 th -14 th centuries ur ban population were 6 years lower than that of the medieval rural population represented by the materials of burial mounds of the 11 th -13 th cen turies (Емельянчик 2015a, p. 322).
Cribra orbitalia (porosity and hyperostosis of the superior wall of the orbits) is currently con sidered to be an indicator of stress due to mal nutrition and increased pathogenic load. Like demographic indicators, cribra orbitalia is a kind of generalizing criterion of the ancient population health status. Analysis of the incidence of cribra orbitalia in different populations allows a com parative assessment of the population general health status without taking into account the specific paleoepidemiological situation.
The group of Polotsk medieval population is characterized by increased frequencies of cribra orbitalia. Among adults, the indicator is present in 32.2 % of cases, among children -in 55.5 % of cases. These indicators are higher than those of the medieval rural population (14.7 % among adults and 50 % among children). The differences in the frequencies of cribra orbitalia between medieval groups of rural and urban populations achieve sta tistical significance (χ 2 = 4.6, p < 0.05).
Discussion. In general, higher incidence of cribra orbitalia were characteristic for the popu lation of Polotsk 13 th -14 th centuries, as well as increased mortality compared to the medieval ru ral population. This indicates the deterioration in living conditions and the general state of health of the studied group of urban population in com parison with the earlier rural population.
As a hypothesis explaining the deterioration of the general health status of Polotsk residents compared with the rural population, we can con sider the factor of urbanization. The negative im pact of the urban environment was noted by A.P. Buzhilova in her study of a number of ancient Rus' cities. In particular, in urban groups there is an increase in the incidence of cribra orbitalia and tooth enamel hypoplasia, as well as a wider spread of bacterial infections, such as tubercu losis and syphilis (бужилова 2005, p. 241, 242). These facts A.P. Buzhilova explains as the result in the increase of urban population density, in some cases -insufficient or poor-quality nutri tion (бужилова 2005, p. 241).
In addition to the noted factor of urbanization, one of the possible reasons for the deterioration of the general health of the Polotsk population in the 13 th -14 th centuries there could be climate chang es that began in Europe in the fourteenth cen tury. On the eve, in the 10 th -13 th centuries, the so-called «medieval climatic optimum» was observed, the era of a relatively warm climate. However, from the beginning of the 14 th century the period of relative cooling began, which lasted until the 19 th century (борисенков 1988, p. 175). The direct consequence of the first phase of this so-called «small ice age» was the mass famine of the first half of the 14 th century in Europe. Only in the 14 th century in the annals there are more than 100 extreme natural phenomena, which resulted in 30 hungry years (борисенков 1988, p. 179). A confirmation of the hypothesis of the in fluence of the climatic factor is the recorded ear lier fact of an increase in the frequency of cribra orbitalia among Polotsk rural population land in the 13 th -16 th centuries in comparison with the «mound population» of the 11 th -beginning of the 13 th centuries (Емельянчик 2015b, с. 304).
Conclusions. As a result of the study, the fol lowing conclusions can be drawn. The total male sample of skulls from medieval Polotsk is characterized by meso-dolichocrania, large sizes of the brain. The face is of medium size, orthognathic, well profiled at the level of the cheekbones and slightly flattened at the level of the orbits, with a strongly protruding nose. The female sample of skulls is similar to the male in most indicators, as well as in terms of characterizing the profile of the face and the de gree of protrusion of the nasal bones. According to most craniological characteristics, a series of male skulls from Polotsk of the 13 th -14 th centu ries is similar to a sample of the medieval rural population of Polotsk land from burial mounds of the 11 th -13 th centuries. The differences relate to an increase in the cranial index in the later Polotsk series, which reflects the onset of the ep ochal process of brachycephalization. In addition, Polotsk urban population differs from the rural population in a number of features of the facial skeleton (a higher face, a larger index of facial protrusion, a smaller protrusion of the nose). These differences can be genetically determined and indicate the participation of the alien compo nent in the formation of Polotsk medieval population.
The body length of adult men from Polotsk var ies within 162-175 cm and averages 169.5 cm. The body length of adult women varies within 147-159 cm and averages 156 cm. Compared to the later Polotsk population of the 17 th -18 th cen turies, the medieval urban population was taller (2.5 cm in men and 2 cm in women).
The average age of adult death in the studied group was 35.1 years. The average age of death for Polotsk women was 3 years less than for men. The group of Polotsk medieval population is char acterized by relatively high frequencies of cribra orbitalia. Among adults, the indicator is present in 32.2 % of cases, among children -in 55.5 % of cases.
Compared with the rural population of the 11 th -13 th centuries urban population of Polotsk of the 13 th -14 th centuries had higher mortality rates and increased incidence of cribra orbitalia, which indicates deterioration in general health in Polotsk urban population. The most probable causes of this phenomenon were, on the one hand, negative factors of urbanization, and on the other hand, the cooling of the climate, which began in Europe in the 14 th century and led to deteriora tion in the living conditions of a significant part of the region's population.

MEDIEVAL POPULATION OF POLOTSK ACCORDING TO ANTHROPOLOGICAL DATA
The aim of this study was to analyze human skeletal remains from 13 th -14 th centuries burials discovered on the territory of the Lower Castle in Polotsk, Belarus. The article deals with the morphological characteris tics of medieval urban population and skeletal stress indicators such as mortality and cribra orbitalia.
According to most craniological characteristics, a series of male skulls from Polotsk of the 13 th -14 th cen turies is similar to a sample of the medieval rural pop ulation of Polotsk land from burial mounds of the 11 th -13 th centuries. The differences relate to an increase in the cranial index in the later Polotsk series, which re flects the onset of epoch-making brachycephalization. In addition, Polotsk urban population differs from the rural population in a number of features characterizing the structural features of the facial skeleton (a higher face, a larger index of facial protrusion, a smaller pro trusion of the nose). These differences can be geneti cally determined and indicate the participation of the alien component in the formation of Polotsk medieval population.
The body length of adult men from Polotsk varies within 162-175 cm and averages 169.5 cm. The body length of adult women varies within 147-159 cm and averages 156 cm. Compared to the later Polotsk population of 17 th -18 th centuries, the medieval ur ban population was taller (2.5 cm in men and 2 cm in women).
The average age of adult death in the studied group was 35.1 years. The average age of death for Polotsk women was 3 years less than for men.
The group of Polotsk medieval population is charac terized by relatively high frequencies of cribra orbitalia. Among adults, the indicator is present in 32.2 % of cases, among children -in 55.5 % of cases.
Compared with the rural population of the 11 th -13 th centuries urban population of Polotsk of the 13 th -14 th centuries had higher mortality rates and increased incidence of cribra orbitalia, which indicates deteriora tion in general health in Polotsk urban population. The most probable causes of this phenomenon were, on the one hand, negative factors of urbanization, and on the other hand, the cooling of the climate, which began in Europe in the 14 th century and led to deterioration in the living conditions of a significant part of the region's population.