Tonatiuh Ichan, the House of the Sun, is described in colonial-era Aztec cosmological sources, chiefly the writings compiled by Bernardino de Sahagun and related codex material, as one of the honoured afterlife destinations in Mexica religion, reserved specifically for warriors who died in battle or on the sacrificial stone, and for women who died in childbirth, the latter understood in Aztec belief as having fought and died a warrior's death in the act of bringing forth new life.
Souls destined for Tonatiuh Ichan were believed to accompany the sun, Tonatiuh, across part of its daily journey through the sky, with warriors escorting the sun from dawn to its zenith at noon and the women who died in childbirth, the cihuateteo, escorting it from noon down to sunset, a division of duty that gave this particular afterlife realm an unusually active, ongoing cosmic function rather than simply offering static rest or reward. This destination stood in explicit contrast within Aztec belief to the fate of those who died ordinary deaths, who were understood to travel instead to Mictlan, the general underworld, reflecting how directly Aztec afterlife belief was organised around the specific manner of a person's death rather than a general moral accounting of their life.