Ælfwine of Deira is the brother of a King of Northumbria that died in what year?
Ælfwine of Deira:  He was a son of Oswiu of Northumbria and a brother of Ecgfrith of Northumbria. Ecgfrith of Northumbria: Ecgfrith (c. 645 – 20 May 685) was the King of Deira from 664 until 670, and then King of Northumbria from 670 until his death in 685.
685