The emperor of the Aztecs, Montezuma was captured and held captive by the Spaniards led by Hernan Cortes. When Montezuma was held captive, he grew close to Hernan Cortes and helped him by informing about plots against the Spaniards.
Montezuma also ordered his people to send gold and silver to the Spaniards. His actions directly consolidated more power to Cortes and the Spaniards took over the city eventually after his death.