 At the height of his reign, Henry ruled over a vast territory stretching from the coast of the North and Baltic Seas to the Alps, and from Westphalia to Pomerania.Henry achieved this great power in part by his political and military acumen and in part through the legacies of his four grandparents.Born in Ravensburg, in 1129 or 1131, he was the son of Henry the Proud, Duke of Bavaria and Saxony, who was the son of Duke Henry the Black and an heir of the Billungs, former dukes of Saxony.