Fortifications of the Staro-Lybaevskoye-1 settlement in the forest-steppe Trans-Urals

The defensive structures of the Staro-Lybaevskoye-1 ancient settlement located near Zavodoukovsk in the Middle Tobol region are considered in the paper. It was built on the edge of the terrace, had a pentagonal shape, dimensions of 75 x 65 m, and a shaft protection system with two driveways. The settlement was used for life four times, twice in the early Iron Age and twice in the Middle Ages. Originally, only a wooden fence with guard towers was made and a moat was dug. Large excavations were not organized because of the pronounced terrain relief, that gave a height difference of 2 m, and, taking into account the height of the wooden wall and the depth of the moat, it provided a 3.5 - 4-meter defensive line typical for the Sargatian culture. After the fire, the defensive line was restored in its former form (III-II centuries BC). It is impossible to identify whether the fortifications were used to defend against the enemy or not, as there were no weapon items in the tracks of the fires. In the early period of the Bakal culture (4th-5th centuries), the settlement was surrounded by an earthen wall. Slope of the residual length of about 6 m played the role of natural berm. The volume of earthworks was approximately twice as large as in the Sargatian time, and the inhabitants created a minimum protective boundary of 5.5-6 m in height. The author assumes the aggravation of social and territorial conflicts and the desire to prevent them from being protected from attack at that time. In the 7th-9th centuries, the population poured an earth wall again, almost twice as wide as before, made from the cultural layer of the previous period instead of the laborious displacement of the soil from the ditch to the height. To enhance protection, the earthen wall was supplemented with log structures a little higher than the height of a man, creating a line of about 6 m in height. The found items of armament and soil burials of the Medny Borok cemetery indicate the preservation of the situation of military danger. The author states the tendency of increasing labor costs for the creation of defensive structures, typical for each archaeological culture.