Ibrahim was a bandit during the Crusades. In 1190, he captured Ian Chesterton and, believing him to be hiding money, staked him out in the desert and daubed him with honey to attract ants, believing Ian would give up his secret rather than be eaten.
Ian pretended to cooperate, telling Ibrahmin his money was in his boot. The bandit cut his right leg free, then, when Ian said it was in the other, his left. In this state, Ian fought with Ibrahim, overpowering him. When asked, Ibrahim told Ian that it was not far to Lydda and that he lived there himself. He asked Ian not to kill him and told him Lydda was in walking distance. When Ian asked where his horse was, Ibrahim replied that his brother had taken it.
At El Akir's palace, Ibrahim told Ian that he would be regarded as a saviour if he rid the world of the Emir, adding that he would not betray him. Ian asked Ibrahim to steal some horses for him, from the stables, which, saying that Ian was now truly his brother, he agreed to do.
Having rescued Barbara Wright, Ian returned to Ibrahim, who gave him the horses he had "acquired". The two time-travellers then departed, with Ian saying "farewell, Ibrahim. Don't go acquiring too many things". Ibrahim commented to Haroun ed-Din that this parting was a shame, as Ian's "honest face" could have made them a fortune. Calling Ibrahim a "half-wit", Haroun replied that the soldiers were coming, so they should not linger. Ibrahim retorted "this half-wit has stolen all their horses", to which Haroun responded that they still had legs. (TV: The Crusade)