March, a British god of the Under World, [316], [327], [329], [335], [338].

Mark, King, [327], [328].

Mars, [51], [204].

“Master of All Arts”, see Ioldanach.

Mâth, a British god, brother to Dôn, [260], [265], [266], [268], [308], [310], [322], [329], [360], [361], [364];

meaning of his name, [260];

teaches magic to Gwydion, [260];

rules from Caer Dathyl, [308];

compared with Merlin, [360], [361], [362].

Matholwch, king of Ireland, [289]-293.