SHIA: Tell me who Prince Aga Khan is?

In Shia Islam, there is a sect called the Ismailis, who do not believe in all the 12 Imam, they believe until the 6th Imam, then they believe that his other son, Ismail was the 7th Imam rather than Imam Musa Kadhim..they are the most liberal of the shia and Prince Aga Khan is the leader of their community