Solomon's Temple
Solomon's Temple was a temple that was believed to be the first of the ancient religion of the biblical Israelites, originally constructed by King Solomon on the hill called Moriah in Jerusalem. It was designed to hold the Ark of the Covenant and a Piece of Eden.
Assassin's Creed
Altaïr, Malik and Kadar were sent to the temple to secure the Piece of Eden during the start of the game. Upon arrival, Altaïr violated the first tenet of the Creed by murdering an innocent bystander. Malik chastised Altaïr's arrogant dismissal of their ways as they continued on. In the primary chamber, they found Robert de Sable and his men were already there to retrieve the artifact for themselves. Altaïr imprudently attacked de Sable, who deflect the charge and delivered a cryptic warning to the brash assassin. He then hurled Altaïr through a support beam, cutting him off from the chamber and his companions. Altaïr believed the mission failed and retreated to Masyaf to report the events to Al Mualim, leaving Malik and Kadar for dead. Malik however did not perish, and managed to retrieve and deliver the Piece of Eden to his master, losing his left arm and his brother in the process.
Altaïr's arrogant actions and violation of the three tenets of the Creed in Solomon's Temple led to his demotion to the rank of Novice and were the catalyst that led to the events of the first game.