Welf IV. (d. ca. 1101)
Duke of Bavaria (as Welf I., 1070)
Count of Altorf (Weingarten)
Founder of the "Younger House of Welf"

Detail from the family tree of the Welfs, in Historia Welforum,
Weingarten Monastery (between 1185 and 1191)
© Hessische Landesbibliothek, Fulda

In this picture, Welf IV. appears on the right;
his wife, Judith of Flanders, is on the left.