In 4C - 6C. In Ustrushan the emergent in the antiquity cities (Mugtepa in the city of Ura-Thbe, fortifications of Shirin 1 - 3 near Kurkat, ancient fortification in the territory of Khujand and of others) continued to exist and the new well-fortified settlement-castles and cities appeared.

Excavations of the ancient fortification of Shirin 1 (4 km northwest of settlement Kurkat) in the lower flow Shirinsay (near the fall in Syrdarya) were carried out in the 70's under management of Н. Н. Негматов. They showed that the covering layer on this monument relates in essence to 4C - 5C. But here the "business" buildings with the corridor-comb-like planning, which spread in Sogd in 6C - 7C, were excavated.

Since 1974 near the settlement Kurkat, A. Mirbabaev conducted the systematic excavations of cemetery of the fortifications of Shirin 1 - 3 - rock tombs, cut in the eastern and southern slopes of the mountain of Shirin at the height 50 - 60m of the foot, at small distance one from another, by groups or according to one. Tombs consisted of funeral niches and funeral cameras (their area from 6 to 11 square meters, the height of ceiling 2 - 2,2 m). In all the operating time, more than thirty tombs and ritual areas -"daxm" are opened. In the tombs also the burials were accomplished in jars and vessels. The substantial part of the burials in the tombs of Kurkat relates to 4C - 6C.

Another tomb in northern Tajikistan - Langari Hojiyon (in the south-eastern outskirts of village of Chorku, region of Isfara) is dated by middle of 1st millennium, also investigated in recent years by A. K. Mirbabaev. Tomb occupies area of approximately 10 ha, the basic types of burials - ground pits with the collective and single burials in the catacombs, the side-holed and the made of planks coffins. The materials of this tomb are valuable addition to the studies, carried out earlier (in the 50's) the tombs of northern Tajikistan and Kirghizia second fourth of 1st millennium: the tomb of Langari Hojiyon demonstrates new stage in the development of funeral rite in this territory.

Excavations of one of the early castles in northern Tajikistan, which is two-part hill of Tudai Kalon (height of 10 m; the height of site-palace of 2,5 m) in 10 km to the south from the villages, gave valuable stratigraphic materials. Asht was investigated by E. D. Saltovskoi in 1962 - 1967. Initially, it (end of 3C - beginning of 5C) was square in the plan well-fortified settlement with the extension rectangular two-story towers along the angles. In 5C - 6C, two-level castle with the large ceremonial hall in the centre was built for defence of the spot of this. Buildings of the third period were incompletely preserved and dated 7C - 8C. For the territory of northern Tajikistan (and the Valley Fergana as a whole) the results of excavations on this monument could be grounds of date, and here the stratigraphic complexes were selected as criteria.

These data are substantially supplemented to studies of other monuments of early-Middle Ages in northern Tajikistan. First of all, it is from layers 5C - 7C on Mugtepa fortification in the city of Ura-Thbe, which chronologically precede (as finding from Tudai Kalon) basic early-Middle Ages complexes from northern Tajikistan. And it is from the excavations of the monuments near Shakhristan, which hide the ruins of Bunjikat, the capital of Ustrushan in 7C - 9C, and from the castles located around.

It is necessary to note ossuari, found on the territory of the Reservoir Kattasay, whose facial wall - this is the miniature image of the facade of the palatial building (such or very close temples are already excavated in Tajikistan - for example, temples in Penjikent).