Henry the Proud (c. 1108 – 20 October 1139) was the Duke of Bavaria (Henry X, 1126–1139), Duke of Saxony (Henry II, 1137–1139), and Margrave of Tuscany (1137-1139).

He was the son of Henry the Black, Duke of Bavaria, and Wulfhilde, daughter of Magnus Billung, Duke of Saxony, and thus a member of the Welf family, and, what was quite important, senior heir of the Billung family. His father and mother both died in 1126 (father became a monk shortly before his death), and as his elder brother Conrad had entered the church and died before their parents, Henry became duke of Bavaria. He shared the family possessions in Saxony, Bavaria and Swabia with his younger brother, Welf.

In 1127 he was married to Gertrude, the only child of Lothair III, Holy Roman Emperor, whose marriage and inheritance Henry's father had been promised as reward for his changing to support Lothair in the royal election of 1125. Gertrude was heir of the properties of three Saxon dynasties: the House of Supplinburg, the Brunones, and the House of Northeim. The couple had only one son, Henry the Lion. After the marriage, Henry took part in the warfare between the king and the Hohenstaufen brothers, Frederick II, Duke of Swabia (who was Henry's brother-in-law, having been married with his sister Judith), and Conrad, Duke of Franconia, afterwards the German king Conrad III. While engaged in this struggle Henry was also occupied in suppressing a rising in Bavaria, led by Frederick, Count of Bogen, during which both duke and count sought to establish their own candidates in the Bishopric of Regensburg. After a war of devastation, Frederick submitted in 1133, and two years later the Hohenstaufen brothers made their peace with Lothair. In 1136, Henry accompanied his father-in-law to Italy, and taking command of one division of the imperial army marched into southern Italy, devastating the land as he went. Having distinguished himself by his military abilities during this campaign, Henry was appointed as margrave of Tuscany and as Lothair's successor in the Duchy of Saxony. He was also given the former properties of Matilda of Tuscany.

When Lothair died in December 1137, Henry's wealth and position made him a formidable candidate for the German crown, but the same qualities which earned him the cognomen of "the Proud", aroused the jealousy of the princes and so prevented his election. The new king, Conrad III, demanded the imperial insignia which were in Henry's possession, and the duke in return asked for his investiture with the Saxon duchy. But Conrad, who feared his power, refused to assent to this on the pretext that it was unlawful for two duchies to be in one hand. Attempts at a settlement failed, and in July 1138 Henry was deprived of his duchies. In 1139 Henry succeeded in expelling his enemies from Saxony and was preparing to attack Bavaria when he suddenly died in Quedlinburg Abbey. Henry was buried in the Collegiate Church of Königslutter next to his parents-in-law.

His son was Henry the Lion, who was underage. Henry's duchy of Bavaria was given to Leopold IV, Margrave of Austria, a half-brother of the new king Conrad. Saxony, which he had attempted to hold but was not officially invested with, was given to Albert the Bear, son of the younger daughter of the last Billung duke, Magnus.

Burial:
Konigslutter Monastery
Braunschweig
Braunschweig
Lower Saxony (Niedersachsen), Germany