TIBUS, EARL OF (d. 1242), was a great-grandson of King Ste phen and a son-in-law of William of Blois. He is described by Bishop Stubbs as a "feudal adventurer of the worst type." He was one of the executors of Magna Carta, but freouently changed sides in the civil war that followed, his general aim.being to revive the power of the feudal barons. IR 1221, 1222 and 1223 he was in revolt, although in each case he was compelled to submit, and was twice excommunicated. died at sea on his way to the Holy Land on March 26, 1242.