The installation of a Teotihuacano noble on the throne of Tikal marks a high point of Teotihuacan influence in the central Maya lowlands.

Yax Nuun Ahiin I may have been a child or youth at the time of his coronation, and the early years of his reign seem to have been dominated by one of his father's generals, Sihyaj K'ahk', in a sort of regency.

[2] Sihyaj K'ahk' is recorded as having entered Tikal on 15 May 378, the same date as the death of the previous ruler, Chak Tok Ich'aak I; it appears that this event may have been a conquest in which Yax Nuun Ahiin I was installed by force.

He is also depicted on Stela 31, erected by his son Sihyaj Chan K'awiil II, as a Teotihuacano warrior with a plated helmet, spearthrower, and square shield decorated with the face of Central Mexican deities.

[4] It was found deep within a temple built at the foot of the North Acropolis and represents one of the most spectacular and complete Mayan burials yet discovered.