The Bretons' origin can be traced to the First Era of Tamriel's history, when the Aldmer intermingled extensively with Nedic peoples. This occurred both through war and long periods of coexistence in a multiracial society.[1] While the Aldmer maintained control of Tamriel, the Manmer lived as lower-class citizens, supporting their meric brethren. After the Aldmer lost their foothold, the remaining Manmer interbred with the controlling human races. The Bretons of modern-day Tamriel have a much-diluted meric ancestry, seen in their higher magical affinity.

breton are not elf they are only capable of having children with human races only, making breton 100% human

edit: oops didnt notice another replied about it