Where does “Llewelyn” come from?

Llewelyn is an English adoption of the Welsh name Llywelyn, which derives from Proto-Brythonic Lluɣβelen, ultimately from Proto-Celtic Lugus.

Ancestry of “Llewelyn”, step by step

StepLanguageWordMeaning
1WelshLlywelyn—
2Proto-BrythonicLluɣβelen—
3Proto-CelticLugusthe god {{w|Lugus}}
Every word from Proto-Celtic Lugus →Every word from Proto-Brythonic Lluɣβelen →Every word from Welsh Llywelyn →