Radulf (Middle English) comes from Old English Rǣdwulf, from Proto-Germanic *Rādawulf, from Proto-Germanic Rēdawulfaz, from Proto-Germanic rēdaz, from Proto-Indo-European Hréh₁dʰos, from Proto-Indo-European Hreh₁dʰ-, from Proto-Indo-European h₂reh₁-, from Proto-Indo-European h₂er- — to fit, to fix, to put together.
Ancestry of “Radulf”, step by step
Radulf traces back through 3 separate lines of ancestry.