|Luis de Santángel|
Luis de Santángel (unknown – 1498) was a baptized Jew born in Valencia and the finance minister of King Ferdinand II. He introduced the explorer Christopher Columbus and his voyage plans to Queen Isabella I, and financed most of Christoffa's voyage.
Luis joined the Assassin Order some time prior to 1491. He and fellow Assassin Raphael Sánchez became close to Queen Isabella and King Ferdinand to prevent the Templars from getting complete control over the monarchy.
Journey to ItalyEdit
Eventually, he met with Christopher Columbus, who had plans to sail west. The Assassins and Templars both knew of another continent, America, and informed Columbus of this. Rodrigo Borgia, leader of the Templar Order, found out about Columbus' planned journey and arranged a meeting with him, claiming he wanted to finance the journey.
Luis suspected the meeting to be a trap and contacted the leader of Venice's thieves and fellow Assassin, Antonio de Magianis, to help him protect Columbus. Antonio then called Ezio Auditore da Firenze for the job, who accepted after he heard that Borgia was involved. Ezio arrived just in time to rescue Columbus.
Taking down the Spanish InquisitionEdit
Luis returned to Spain along with Columbus and met with Ezio again some time later. He revealed himself to be an Assassin as well. He then guided Ezio in eliminating the Templars' plans to take down the Spanish Assassins. He also introduced Ezio to Queen Isabella, after he had ended the war between her and King Muhammad XII. Luis convinced Isabella to partially finance Columbus' voyage, paying for the other part himself.
Not too long after that, Luis was threatened by the Inquisitors, so Ezio set out to take the life of the Inquisitor General Tomás de Torquemada. However, Ezio found out that Tomás wasn't a Templar himself and was just fooled into taking down the Assassins by Rodrigo Borgia. Thus, he spared his life before returning to Italy.
Luis kept serving the Spanish royal house, but started poisoning Isabella, either as revenge for the Inquisition, or because of her connection to the Templars. However, he died in 1498, before he managed to fulfill his plans. 
With his death, there was no one to inform the other Assassins of the Templars' activities in the royal house. Therefore, Ezio Auditore sent his apprentices to Spain to recover Santángel's journal in 1503.