<P> This is a timeline of Mexican history, comprising important legal and territorial changes and political events and improvements in Mexico and its predecessor states . To read about the background to these events, see history See also the list of heads of state of Mexico and list of years in Mexico . </P> <Table> <Tr> <Th> Year </Th> <Th> Date </Th> <Th> Event </Th> </Tr> <Tr> <Td> 1520 </Td> <Td> 20 May </Td> <Td> Massacre in the Great Temple: Spanish soldiers killed a group of Aztec nobles in the Templo Mayor in Tenochtitlan during the celebration of Toxcatl . </Td> </Tr> <Tr> <Td> 29 June </Td> <Td> Spanish conquest of the Aztec Empire: Moctezuma II, the tlatoani of Tenochtitlan and ruler of the Aztec Triple Alliance, was killed . </Td> </Tr> <Tr> <Td> 30 June </Td> <Td> La Noche Triste: The Spaniard Hernán Cortés lost several hundred men in a fighting escape from Tenochtitlan . </Td> </Tr> <Tr> <Td> 7 July </Td> <Td> Battle of Otumba: Combined Spanish and Tlaxcala forces seriously defeated a vastly superior Aztec force at Otumba de Gómez Farías . </Td> </Tr> <Tr> <Td> 1521 </Td> <Td> 13 August </Td> <Td> Fall of Tenochtitlan: Tenochtitlan was taken by Spanish forces . The tlatoani Cuauhtémoc was taken prisoner . </Td> </Tr> </Table> <Tr> <Th> Year </Th> <Th> Date </Th> <Th> Event </Th> </Tr>

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