John, Duke of Brunswick-Lüneburg

John (c. 1242–1277) of the House of Welf ruled Brunswick-Lüneburg with his brother Albert after their father Otto the Child died in 1252. The brothers partitioned the duchy in 1267–1269: John took the northern estates around Lüneburg and Hanover, founding the Old Line of Lüneburg.

In a feud with Count Gunzelin of Schwerin he won Uelzen and granted it privileges in 1270. He failed to control the Lüneburg saltworks, then gave the citizens a salt-trade monopoly along the Old Salt Route to Lübeck. His son by Liutgard of Holstein succeeded him as Otto II the Strict, under his uncles' guardianship until 1282.