Henry IV (1050-1106) was Holy Roman emperor and king of Germany from 1056 to 1106. An able, ruthless, and secretive monarch, he led the empire into a disastrous confrontation with Pope Gregory VII in the Investiture Controversy.

Born in Goslar, Saxony, Henry IV was the only son of Emperor Henry III and Agnes of Poitou. His father died when he was only 6, and he had a long and difficult minority as king, since early in 1062 he was taken from his mother and raised by a bevy of quarreling, scheming bishops. In 1066 he came of age and began governing on his own. He was married twice, first to Bertha of Savoy and late in his reign, after her death, to Praxedis of Russia.

Henry attempted, initially, to reassert his father's old imperial rights throughout the empire and also to build up a new, strong imperial domain in Saxony. This led to...