The Lion was his heraldic animal.
Henry achieved this great wealth in large part by the combined legacies of his four grandparents. He was the son of Henry the Proud, duke of Bavaria and Saxony, who was the son of duke Welf IV and an heiress of the Billungs, former dukes of Saxony. Henry's mother was Gertude, only daughter of the Emperor Lothar II and of Richenza of Nordheim, heiress to the Saxon territories of Nordheim and Brunswick-Lüneburg.
Henry's father died in 1139 when Henry was still a child, and King Conrad III did not immediately give the two dukedoms to Henry. He acquired Saxony in 1142, and Bavaria in 1156.
He is the founder of Munich (1157/58; München) and Lübeck (1159); he also founded and developed the cities of Stade, Lüneburg and Braunschweig (city) (Brunswick), where he had a bronze Lion erected on his castle yard, next to the Brunswick cathedral, in 1166 – the first bronze statue north of the Alps, which still exists today (see "Brunswick cathedral" for a photo).
He made Brunswick the capital of his principality. The lion demonstrates his power which was nearly that of a king.
In 1158 he married as his second wife Matilda (1156 -1189) the daughter of Henry II of England and Eleanor of Aquitaine.
In 1175, Henry the Lion refused to aid his cousin Emperor Frederick I, against Lombardy, because he did not accept the condition of investing him with the rich city of Goslar. It was this insubordination the Emperor could not tolerate. Henry had to face a feudal lawsuit and was condemned in 1180, losing most of his principality. He had to leave Germany in 1182 for three years and stayed with his father-in-law, Henry II.
The last years of his life Henry the Lion tried to gain back what he had lost, but he mostly failed.
The picture on the top right, taken from his tomb in Brunswick cathedral made between 1230 and 1240, shows an idealized image. When the Nazis exhumed his corpse in the hope of finding a symbol for their ideology of a superior German race, they were disappointed finding a comparably small man with black hair.