The Yongmin were founded by Seung Il Jong, a former Republic general and senator in the year 780 RC. The Yongmin was a privately funded military organization created to fight the increasing Terran presence in the Colonies and the Mid Rim.
The Yongmin were led by a Council of leaders, each with different backrounds. The Independent Mining Corporation's shareholders all had a Council seat, basically making the Corporation a front for the Yongmin. The Council also included a few senators, who never made an actual appearance, but their opinions and descisions were expressed rarely in letters.
The Yongmin had a large military. The Yongmin Starfleet consisted of hundreds of small frigates. Eventually around 1160 the Yongmin was supplied by the Republic with Star Destroyers. This earned the ire of the United Terran Kingdom. However since the Yongmin funds where retrieved from various senator's personal accounts from outside the Republic, The Terrans could not really attack them. The Yongmin also had a large standing army.