Lisbon (Portuguese: Lisboa) is the capital city of Portugal. During the Renaissance, a guild of the Assassin Order was based in the city and received aid from Ezio Auditore da Firenze's Italian guild.
Knowing that Manuel I of Portugal might have connections to the Templars, the Assassins traveled to Lisbon and interrogated one of the men in his council, who revealed that Manuel did indeed serve the Templar cause. They also learned that Manuel was preparing to send a fleet, led by Vasco da Gama, to Calicut. This prompted the Assassins to warn their brothers in India.
Shortly after that, they learned that Manuel was forcing the city's entire Jewish population to either convert to Christianity or leave, but had also closed the city borders, making it impossible to escape. Anyone who refused to convert was beaten or even killed. The Assassins arranged for three ships to take the Jewish citizens out of Lisbon, though it was not enough and the Assassins were forced to kill many guards that had found out about their plans.
Knowing that they could not get all the citizens out in time, they provided them with weapons and light armor, training them in tactics such as stealth, surprise, intimidation and shock. The civilians seemed eager to fight their king, and very few of them accepted the offer to travel to Italy with the Assassins.
In November of 1755, the Assassin Shay Cormac was sent to Lisbon by his Mentor, Achilles Davenport, to retrieve a Piece of Eden from within a Isu temple hidden beneath the Carmo Convent. Shortly after Shay removed the Piece from its pedestal, it disintegrated and the earth began to quake. Though Shay managed to escape from the disaster and sail back to the Thirteen Colonies, this massive earthquake collapsed multiple structures and killed countless civilians throughout the city.