Alexander was a one-time resident of Platonius who later served as a Federation ambassador for over one hundred years.

Although the Platonians were generally human-sized, Alexander was a dwarf who served as a slave to the rest of the Platonians.

In 2268, the USS Enterprise arrived at Platonius. Some members of the crew were taken prisoner, but they eventually escaped and took Alexander with them. (TOS episode: "Plato's Stepchildren")

Alexander eventually began serving as a Federation ambassador - a position which he held for over one hundred years prior to visiting S'ti'ach'aas as a representative of the Federation. His size (roughly the same size as a S'ti'ach) as well as his wisdom and sensitivity were pivotal in convincing the S'ti'ach that they could participate in the Federation as equals. (TTN novel: Orion's Hounds)