Bartimaeus in Ptolemy's form
Ptolemy (138 BC–124 BC) was the most notable of Bartimaeus' old masters, being both fair and kind. He wanted peace between demons and magicians, rather then the slavery that existed between the two factions. To prove his loyalty, and his trust towards Bartimaeus, he created the Gate of Ptolemy which allowed him to visit Bartimaeus in the Other Place for once putting the power in a demon's hands. However, his trip to the Other Place weakened him giving his cousin, the heir to the Egyptian throne, room to manuever and kill him.
His cousin thought, due to his popularity among the people and the power at which he controlled his demons, he was going to try and take over the throne. Ptolemy was killed by his assassins at the young age of 14. But despite his inevitable death he freed Bartimaeus, who at the time was under his command, even though he would have stood and fought to the death for Ptolemy. Thus he gave Bartimaeus one more precious gift, among numerous others, before he met his demise.
Compared to most magicians Ptolemy had very little ambition, and would prefer to talk to demons than make them do his bidding (although his bidding was mostly answering questions), and there is no reference of him using any of the typical demon punishments. Because of this, he earned their respect and loyalty as well as their trust, giving Ptolemy a unique bond between his demons that no other magician before or since has shared between his slaves. This bond stretched so far that Ptolemy's only surviving demon, Bartimaeus, out of respect still wears his guise to this day.
Ptolemy's method for creating the Gate of Ptolemy was recorded in his Apocrypha, published after his death, but most magicians regarded it as a speculative fantasy.