The ancient Maya concept of 'deity', or 'divinity' ("k'u" in Yucatec, "ch'u" in Ch'ol, and "qabuvil" in ancient Quiché) is poorly understood, but can by no means be reduced to a mere personification of natural phenomena. The life-cycle of the maize, for instance, lies at the heart of Maya belief, but the role of the Maya maize god transcends the sphere of agriculture to embrace basic aspects of civilized life in general (such as writing). Deities have all sorts of social functions, related to such human activities as agriculture, midwifery, trade, and warfare. Moreover, they can be the patrons of large kin-based or ethnic segments of society, as shown by the four deities presiding over the four wards of Itzamkanac; the Popol Vuh Triad (including Tohil); and possibly also by the Palenque Triad (G I, II, and III) and its Classic Period analogues elsewhere.