But for poorest Russians, life not improve. By the end of her rule, serfs-poor farm workers-comprised more than half the male population of Russia. As Catherine increased the power of the nobility, whose support she needed for her reforms, the rights of serfs disappeared. In 1773, rebellion broke out. Several nobles were murdered, and their estates were destroyed. Catherine had to rely on her military to put down the rebellion, preventing the serfs from marching into Moscow. The incident affected Catherine deeply, and she abandoned any further serious attempts at social reform.