The boyars were members of the upper nobility in Russia from the 10th through the 17th century. Their military support of the Kievan princes initially earned them influence and government posts, but soon land ownership became the main source of their power and prestige. The boyars continued to advise the prince through a council, but as the Moscow grand princes consolidated their power, their influence was gradually eroded until which czar abolished the rank and title of boyar? Discuss
Source: The Free Dictionary