The Columbia Encyclopedia, Sixth Edition. 2001-07.
Feodor III
166182, czar of Russia (167682), son and successor of Alexis. Although an invalid, Feodor strove to carry out reforms. In 1681 he abolished the system of precedence among the boyar families, whereby appointments in civil and military service were based on social rank rather than on merit. He was succeeded jointly by his brother Ivan V and his half brother Peter I under the regency of his sister Sophia Alekseyevna.