This is Æthelwealh

The King of Sussex from 660-685 AD, 

when Bognor was established.

He was a Celt.

First Christian king of Sussex, converted by Bishop Wilfred of York. Killed by Cædwalla of Wessex. 

In 661, king Wulfhere of Mercia gave Æthelwealh the territories of Meonwara and the Isle of Wight.

Gemini