Henry was a son of Margrave John I of Brandenburg and his second wife, Jutta, the daughter of Duke Albert I of Saxony.
Henry was more than fifteen years younger than his brothers John II, Otto IV "with the arrow" and Conrad I and was therefore likely to be excluded from governing when his brothers inherited the Margraviate.
When he did, he received — according to an excerpt from the Bohemian chronicler Přibík Pulkava — Delitzsch as his seat.
Henry I appears to have declined the proposal, and his promised by deed to vote for Duke Frederick the Fair or his brother Leopold I.
However, in the end, Henry voted for Duke Louis IV of Bavaria.