Henry the Mild, Duke of Brunswick-Lüneburg
Henry of Brunswick-Lüneburg (Latin Henricus, died 14 October 1416), Duke of Brunswick-Lüneburg, called Henry the Mild, was prince of Lüneburg from 1388 to 1409 jointly with his brother Bernard I, Duke of Brunswick-Lüneburg, from 1400 to 1409 also of Wolfenbüttel, and from 1409 until his death sole prince of Lüneburg.

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. Only in 1405, a peace was ratified between Brunswick-Lüneburg and the Archbishopric.

In 1404, Henry was kidnapped by Bernard VI, Count of Lippe; when he paid a ransom, he was released, and later, with the support of King Rupert, took revenge on Bernard.

After the death of Gerhard, Count of Schleswig, Henry's sister's husband, Queen Margaret I of Denmark tried to take control of Schleswig, but Henry, together with Holstein, successfully defended Schleswig.