Welf I of Bavaria

Welf I (c. 1035/1040 – 6 November 1101) was Duke of Bavaria from 1070 to 1077 and again from 1096 until his death. He was the first member of the House of Welf branch of the House of Este. In the genealogy of the Elder House of Welf, he is counted as Welf IV or simply Guelf.