Where does “Bretun” come from?

Bretun (Old French) comes from Latin britto, from Latin Brittania, from Ancient Greek Βρεττανία, from Ancient Greek -ῐ́ᾱ, from Proto-Indo-European -íh₂, from Proto-Indo-European -h₂ — Creates collective nouns, which refer to groups...

Bretun (Old French): Breton person; Britton

Definitions

Breton person; Britton

Ancestry of “Bretun”, step by step

Step	Language	Word	Meaning
1	Latin	britto	a Briton
2	Latin	Brittania	Britain
3	Ancient Greek	Βρεττανία	the British Isles
4	Ancient Greek	-ῐ́ᾱ	{{l\|en\|-ia}}; "suffix forming abstract feminine...
5	Proto-Indo-European	-íh₂	—
6	Proto-Indo-European	-h₂	Creates collective nouns, which refer to groups...

Every word from Proto-Indo-European -h₂ →Every word from Ancient Greek -ῐ́ᾱ →Every word from Ancient Greek Βρεττανία →