The Patricians are those of noble blood, which leads back to the time of the Old Kingdoms. As they were the richest of all citizens in Solace, and those who could vote and run for office in the High Council, the Patricians were the ruling class for 706 years.
After The Magi took control, the Patrician's authority is greatly reduced, but those loyal to The Magi have retained much of their previous power.
Each noble family controls a vast tract of land on the flying islands. As such, they have always had control over the prices of natural resources. Since The Magi began ruling Solace, they have retained their land, but now give the vast majority of their produce directly to the state.