The danger, coming from Moscow princes, and the threat of Khans’ intestine wars made the Kazan nobility strive for independence and their own state formation. Thus, when Ulug-Mukhammed khan came with his armed forces to the boundaries of Kazan estates in December of 1438, the Kazan aristocracy entered into alliance with him. By the time, he had been expatriated from the Lower Volga Region and was fighting with the great Moscow prince Vasily the Dark (II). There are no any references to the fact, if Ghiyas Ad-din had ever been overthrown and if Ulug-Mukhammed had ever been proclaimed as a khan, but the participation of Kazan troops in the campaigns against Russia is doubtless. In any case after the victory over Moscow in 1445 and Ulug-Mukhammed’s death, his son Makhmudek was proclaimed as the khan of sovereign Kazanian Khanate.

In the XV-XVI centuries the Kazan citadel occupied almost all territory of the contemporary Kremlin complex. From the South it was limited to the fortification, built on the edge of the so-called Tezitsky gully. The fortification consisted of deep (up to 3 meters) fosse and a rampart. Wooden walls like a framework of 6-7 meters width, filled with soil, were built over the rampart. The fortification area was of 13 hectares. As excavations showed, there were a lot of constructions, mainly of wood, inside the citadel.

The leavings of the Tsar’s palace were found in the North-Eastern part of the Kremlin (the place, where the President’s Palace is situated now). It occupied the major part of the Kremlin Hill. White-stone walls, which had appeared earlier, protected the palace. A white-stone mosque Nur-Ali was situated on the territory of the palace. It had a high minaret not far from the Syuyumbika Tower close to khan’s mausoleums. All of them were square and built of white stone. Plaster tombstones with rich ornamentation were found inside them. Under the tombstones in two coffins, put one into another, there were remains, buried in accordance with Moslem rite. Just here, inside the citadel, some parts of wooden and brick estates’ constructions, such as houses and household buildings were found alongside the part of a big white-stone building, which could have been a khan’s palace.

Towards the Southern part of the citadel, near the Tezitsky gully, there was a mosque and a Kul-Sharif medrese (religious school). A large trading quarter adjoined the citadel from the south and south-west. According to the excavations, it occupied the place in Lobachevsky Street from the East, lakes Bannoye, Chyornoye and Poganoye from the north, the right bank of the Bulak River from the west and Tashayak street from the south. The Kazan trading quarter was walled and had gullies around even in the middle of the XV century. They were renewed and reconstructed regularly. The gully was of 15-20 meters width and 3-4 meters height. Hardwork, pottery, woodwork, stone-cutting and tanning industry, jeweller’s art and war industry prospered in the city. Besides, several cemeteries were situated both in the city and beyond it. A tombstone dated 1530 was taken from one of them. The cemetery occupied the area, where the State Museum of the Tatarstan Republic is located now. Big cemeteries of the XV-XVI centuries have been found in the area of K. Nadzhmi Street and the contemporary building of physics department of the Kazan state university.

Large villages and settlements were situated around the city. One of them, Kuraisheva, was located on the left bank of the Bulak River. The leavings of its cemetery have been found several times in the area of the contemporary central market. A large village of carpenters and shipbuilders “Bishbalta” (“Bezhbolda”) was famous as well. A site of merchant and war ships of the Kazan citizens had been here, in the creek of the Kazanka river mouth.

There was an Armenian village with its own cemetery (tombstones dated the XIV-XVI centuries) to the south of the city, on the hills (in the area of Kalinin Street). Many settlements and beks’ and murzs’ residences were situated in the suburbs of Kazan. Some of their names, such as Kul-Mametovo (Kul-Mukhamed), Ametyevo (Akhmed) and others are used in the city toponymy. According to later chronicles, the residence of the Kazan khans, including the Syuyumbike gardens, were located near Lake Sredny Kaban.

In 1552 the city was taken by storm after seven-week siege by the Ivan the Terrible (IV) army. Iadgar khan was captured. Archaeologists found people’s bones and stone cannon-balls in the fire layer. The city was completely ruined. Its population either were killed or taken prisoners and evicted to the other side of Lake Kaban. However, the struggle for liberation didn’t stop. Occasional revolts and campaigns had been organized up to the year of 1557.