The Teulu were the bodyguards of the Romano-British warlords. Teulu means "family" in Welsh, and that was mostly what they were, but they could be friends, allies or clientes also. Anyway they were really similar to the Macedonian Companions.
In this picture you can see a couple of members of Arthur's Teulu: the brothers Gwalchmai and Gwalchafed. Known as Sir Gawain and Sir Gaheris thanks to medieval literature. They were sons of Lot Luwddoc of Gododdin and Elain, and nephews of Arthur.