The Basilikon Agemata is the elite guard of the Ptolemaic king, an elite phalanx force of veterans of several origins.
The Ptolemaioi had a problem with their elite infantry from the start. Namely, they didn’t have any, since the Seleukeis and Makedones took what remained of Alexandros’ Hypaspistai. Therefore, they had to build a unit of royal heavy infantry to compete with their rivals. Many things were tried, but ultimately the result was the Basilikon Agema, the Royal Guard. They are armed with hoplite spears and thureos shields and armored in mail, making them more mobile but less well armored than other heavy infantry. They also carry a short sword that was used rather like the Romaioi used theirs. This led to the misidentification of these troops by Latin authors as a sort of imitation legion. The Basilikon Agema is full of good troops, mostly Hellenes and Makedonians with a few Galatai and Kretai. They are an elite infantry, well able to fight in a phalanx and to break the formation and fight with their blades. They are extremely versatile and can be used to good effect by a capable commander.
Historically, the Basilikon Agema were the elite guard of the Ptolemaic king. They went everywhere with their king, and were instrumental in putting down several native revolts along with the Galatai. They outfought the natives with creative tactics that worked well against other successor pikemen as well. Most of the unit was not present at Raphia, but was used to good effect against the Seleukeis on other occasions.