Ivan V was the son of
Tsar Alexei of
Russia. He was nearly
blind,
lame, and either had a speech impediment or was retarded (sources disagree) -- in any case, he wasn't going to make much of a tsar. However, after Alexei's older son,
Fyodor III, died in
1682 when Ivan was sixteen, and Fyodor and Ivan's ten-year-old half-brother, later to be known as
Peter the Great, was selected to be tsar, Ivan's sister
Sophia protested and led an uprising to get Ivan made co-tsar and herself
regent for both.
Ivan himself had no ambition to be tsar, and some of Sophia's supporters were known to have laughed at her using his name in her efforts to gain power. The two tsars only came together on formal occasions when Sophia needed them as figureheads, but they always got along very well, and in 1689 when Peter was able to seize power from Sophia, Ivan's position was unchanged. In fact, Ivan saved Peter from having to deal with the strict protocol of many formal occasions (which Peter hated), because Ivan could do anything that merely required the tsar's presence for ceremonial purposes. Peter sent Ivan detailed letters when he traveled. Ivan married and had two daughters, Catherine and Anna, who with their descendants were in the line of succession to the crown. He died in 1696, leaving Peter the Great sole ruler of Russia.
Sources: Robert K. Massie's Peter the Great: His Life and World in addition to those listed under Monarchs of Russia.