Answer
Bohemond I was the nephew of the founder of the Hauteville dynasty, Tancred of Hauteville. Bohemond's father, Robert Guiscard, was the sixth son of Tancred and inherited the title of Duke of Apulia and Calabria after the death of his older brothers. Bohemond succeeded his father as the Duke of Apulia and Calabria and continued the family's expansion in southern Italy and the Balkans.