It is likely that Martin was a relative of or close personal friend of the family which owned the Haunted Mansion.
Due to the use of the word Spartan, some falsely assume that the Roman leader seen in the Great Hall sequence. The term Spartan however referred at the time to someone of stern habits and even if taken literally, Spartans were Ancient Greek warriors, not Romans.
In the cast-member created Ghost Gallery, Martin is reimagined as having been an 18th century pirate captain who went by the alias of Whitebeard and who used the Haunted Mansion as a criminal lair. He was also responsible for the piratical training of Captain Francis Xavier who would later become an owner of the Haunted Mansion and the one responsible for relocating Bluebeard's crypt to the Haunted Mansion. In the story, it is said that sometimes sailors passing by the mansion claim to see the ghosts of Whitebeard, Francis Xavier and Bluebeard celebrating together.