The sons of Altaïr Ibn La'Ahad and Maria Thorpe, born in 1195 and 1197 respectively. Both were raised - as Altaïr was - at Masyaf, trained to be Assassins by their father, and diplomats and men of honor by their mother. But unlike Altaïr, who spent most of his early years separated from his father as part of Al Mualim's training, Darim and Sef grew up in a house full of affection and love. Altaïr, though often stern, was a patient father too, a man determined to give his sons what Al Mualim had given him - guidance and respect.
Sef married quite young, and after his untimely death his family moved to Alexandria at some point in the first half of the thirteenth century. It is unknown whether or not Darim had any offspring of his own, but we do know he eventually joined his brother's widow and children in Egypt.