It is simply untrue as far as we can yet tell that there was ever a time or place where the complex family was the universal background to the ordinary lives of ordinary people.
--Laslett and Wall (1972:xi)

"Y nican icha ytoca... [Here is the home of one named]" is a common refrain in the amazingly complete, but little known, sixteenth century household censuses of ancient Mexico. Written on fig-bark paper by native speakers of the lingua franca of prehispanic Mesoamerica, the Nahuatl censuses must rank among the most detailed in the world for that era. In 1993, a polished, nuanced English translation by the ethnohistorian and philologist S.L. Cline was published for two villages, Huitzillan and Quauhchichinollan, near Cuernavaca, Morelos (Cline, 1993). Reporting a combined population of some 2,500 people grouped in 315 households, these surprisingly detailed documents provide intriguing data on rural Nahua families and households during the first decades of Spanish conquest and colonization. While the Morelos lists do not satisfy all of the basic requirements of a modern census--age for example is not specified for ever-married adults, sex must be determined from naming conventions, and young children are undercounted--these lists are priceless for understanding Nahua society, particularly marriage, residence, and family or household patterns. The Morelos lists also offer unexpected insights on the long-running debate among family historians regarding the frequency of complex households in the past and the principal detriments to household complexity--whether in premodern times the greatest obstacles to the formation of extended families were high death rates, delayed marriage or neolocal residence rules (Levy, 1965; Coale, 1965; Laslett and Wall, 1972; Kertzer, 1989; Hareven, 1991; Smith, 1993; Ruggles, 1994).