Henry was the fourth son of Magnus with the Necklace, Duke of Brunswick-Lüneburg.

He participated in the prosecution of the murderers of his brother Frederick, elected King of the Romans, after 1400.

Henry ravaged the Eichsfeld, a possession of the archbishop of Mainz, who was suspected to be involved in the murder.

Henry married Sophie (died 1406), daughter of Wartislaw VI, Duke of Pomerania, in 1388.

Children were: Henry married Margaret (c. 1389–1446), daughter of Hermann II, Landgrave of Hesse, in 1409.