Where does “Callen” come from?

Callen (English) comes from English Callan, from Irish Ó Cathaláin, from Irish Cathalán, from Old Irish Cathal, from Proto-Celtic Katuwalos, from Proto-Celtic katus, from Proto-Indo-European kéh₃tus, from Proto-Indo-European -tus — Derives action nouns from verb roots.

Ancestry of “Callen”, step by step

StepLanguageWordMeaning
1EnglishCallan—
2IrishÓ Cathaláin—
3IrishCathalánlittle Cathal
4Old IrishCathal—
5Proto-CelticKatuwalosstrong in battle
6Proto-Celtickatusbattle
7Proto-Indo-Europeankéh₃tusfight
8Proto-Indo-European-tusDerives action nouns from verb roots
Every word from Proto-Indo-European -tus →Every word from Proto-Indo-European kéh₃tus →Every word from Proto-Celtic katus →