Why go
The expeditions explain why Cozumel, Tulum's coast and Bahía de la Ascensión enter early colonial accounts, even though Spanish parties did not establish control there. Grijalva observed large shoreline towns before circling the peninsula. Cortés then passed through Cozumel and Tabasco, where Malintzin became central to communication on his later campaign.
The full story
Juan de Grijalva left Cuba in April 1518 and first landed at Cozumel. Maya residents withdrew from contact, and his fleet continued south along the eastern coast. The Spanish saw several large coastal towns, one possibly Tulum, then reached a bay they named Bahía de la Ascensión. Grijalva turned north without landing at those towns and continued around the peninsula. At Campeche, conflict over access to water led the Spanish to fire on the city. Reports of the voyage encouraged a larger expedition under Hernán Cortés in 1519. His fleet called at Cozumel and then moved around Yucatán to Tabasco. After fighting at Potonchán, Cortés received a group of women from the defeated Chontal Maya rulers. One was Malintzin, later called Marina, whose knowledge of Maya and Nahuatl became crucial to communication as the expedition moved toward central Mexico. These voyages mapped routes and relationships, but the coastal Maya remained active participants in each encounter.