John I, Duke of Mecklenburg , was from 1344 to 1352 Duke of Mecklenburg from 1344 to 1352 and Duke of Mecklenburg-Stargard from 1352 to 1392.
Background
He was probably the youngest child from the second marriage of Lord Henry II "the Lion" of Mecklenburg and Anna of Saxe-Wittenberg, a daughter of Duke Albert II of Saxe-Wittenberg. His father died in 1329, and he remained under guardianship until 1344, when he came of age and began to carry a seal as a participant in the governance of Mecklenburg.
Career
John I was probably born in 1326. John, Albert and Charles initially supported the False Waldemar, but in 1350 they reconciled with his supporter Duke Louis V of Bavaria. Upon the division of Mecklenburg on 25 November 1352, John was awarded the Lordships of Stargard, Sternbuerg and Ture.