Lord Wemba was a Saxon warlord active during the 10th century. In 966, the land he and his wife Frida controlled was the site of many border disputes between the Anglo-Saxons and the invading Vikings.
Wemba was a fair-minded lord who wanted to make peace with the Vikings rather than continue the endless fights. He was aware of the Eleventh Doctor's aid to his ancestor, Alfred the Great, and trusted him because of it.
In later years, Wemba's land became the site of Wembley Stadium. (COMIC: They Think It's All Over)