sentences:  The Teotihuacan warlord Siyaj K'ak' is mentioned in an inscription at Río Azul dated to AD 393, during the reign of king Yax Nuun Ayiin I at Tikal.The military costume of Yax Nuun Ayiin I depicted on monuments at both Tikal and Río Azul, combined with a number of hieroglyphic texts, links the Tikal king with the political events at Río Azul at this time.Tikal's dominance over Río Azul at this time would have secured an important trade route to the Caribbean and would have challenged Calakmul, Tikal's great rival, which would have used the Hondo river for its own route to the sea.