Chak Tok Ich’aak must have realized that January 14, 378 A.D., would be his last day on earth. The king of Mutal, the biggest and most cosmopolitan city-state in the Maya world, he lived and worked in a sprawling castle a few hundred yards away from the great temples at the city’s heart. (Now known as Tikal, the ruins of Mutal have become an international tourist attraction.)