With the participation of a narrow circle of close associates he carried out a number of reforms in the 1550s. At the first Zemsky Sobor (Assembly of the Land) in 1549 a law code for the whole of Russia, the Sudebnik, was adopted and a regular army of streltsy – people under arms who carried out permanent military service for pay – was established. The Stoglavy Sobor (Hundred Chapters Assembly) was summoned in 1551 to unify religious rites and deal with matters of canonisation. Ivan conducted successful campaigns to absorb the Khanates of Kazan (1552) and Astrakhan (1556), as well as Bashkiria (1557). He was defeated in the Livonian War to gain access to the Baltic (1558–1583). Clashes with boyar circles opposed to Ivan led to the formation in 1565 of the oprichnina (from the Old Russian oprich, meaning “special” or “apart”) when, after separating off part of the country and the troops under his own personal rule, the Tsar took extreme measures to crush the old boyar families so that power could be further centralised. Ivan supported the development of culture, the building of churches and enlightenment. According to various sources he had as many as seven wives. He was called “Terrible” (Grozny) by the people because of the savage executions of political opponents. Historiography has given him an extremely ambiguous evaluation.