Kingdom of Argos
From dndwiki
A mercantile kingdom that started in the southern Focian plains, the Kingdom of Argos was contemporaneous with the Sarpadian Empire. The Kingdom of Argos existed for 500 years sending out colonies far and wide before succumbing to the same terror that saw the end of the Sarpadians.
There was a very active cult called the Cult of Bhaal within the Argos Irregulars - shock troops wielding murderous killing magic with close ties to the secret police of the kingdom.