Association of Russian lands around of Moscow represented a new stage in development of Russian State system. The Territory of the Moscow State increased significantly and demanded a centralized executive system. Trying to glorify the power of the Grand Duke, the government of Ivan III began to form a multistage system of servicemen. Boyards swore allegiance to the Grand Duke. They supported their oaths by special documents.
The Moscow Sovereign acquired a rights to impose disgrace on boyards, dismissing them from public service, confiscating their ancestral lands or, on the contrary, granting them with new ones. Functions of public administration underwent gradual complication what predetermined separation of the palace management. In the middle of XV century "The Treasury" (subsequently The State Court Yard) was allocated. And in 1467 the posts of the state clerks and their deputies were designated. These people carried out clerical work in this new establishment, which was engaged not only in finance, but also in foreign and internal affairs.
The Boyards Duma - the centralized state structure was formed in the end of XV century. Besides the boyards of the Moscow Duke former apanage princes were also in its structure. The Duma considered crucial political matters and was a legislative body at the same time.
To centralize and unify the order of judicial and administrative activity in 1497 the new code of laws (The Ivan's III Law Code) was assembled. It set unified standards of taxation and the order of investigation and trial. The Code was directed, first of all, on protection of life and property of feudal land owners, and the state as a whole.
It is typical, that one of it's items (# 57) restricted the right of peasants to leave their feudal lord and move to other lands to the certain period of time: one week before to St. George's Day (November, 26) - one week after it with obligatory payment for the time that they had lived on the lands of their former lord (the total sum was about 1 rouble). The code also limited villeinage in cities, thus raising the number of tax bearers among urban population.
The rise of authority of the Grand Duke of Moscow was contributed by Ivan III's second marriage (he married Sofia, a niece of the last Byzantian Emperor Konstantin Paleolog). Ivan III was also greatly supported by the Pope. The Pontiff thought that a treaty could promote unification of Catholicism and Orthodoxy. But this plan met strong resistance of Russian clergy.
November, 1, 1472 Sofia Paleolog and Ivan III married in Moscow following Orthodox ceremony. After that new magnificent ceremonials were introduced at the Moscow Court. The Byzantian two-headed eagle was accepted as a new State Emblem. Monomah's Crown also became a special attribute of the sovereign's power.