San O'dia was founded first as a military fort, to help protect trade routes traveling between Cyran and Lutia from ambushes. Of particular historical note is its shrine to Castrum.
Currently, King Bast presides over San O'dia, although numerous reports of his mental instability have caused the United Merchant's Guild to effectively take over the city. This takeover is essentially public knowledge, although the population has done little to fight against the guild's control--likely due to its extremely strong influence over the city's economy, as well as the guild's ties across Tempus.
Strategically, San O'dia provides relatively safe access to the Char Republic, making it a valuable city for the Kingdom of Jeuno.