Complex sentence: Every 52nd year was a Ce-Acatl year 1467 was such a year that the Spanish conquerors were people sent by the gods (according to orthodox scholarship), so they offered little resistance initially to the advances of the conquerors.
Split into simpler sentences: Every 52nd year was a Ce-Acatl year 1467 was such a year. On their arrival in the new world, the Aztecs thought the Spanish conquerors had been sent by the gods, so they initially offered little resistance to the advances of the conquerors.