Who are the Shia Ismaili Muslims?

The Ismaili Muslims, of which the majority follow the Aga Khan as their Imam and spiritual leader, are part of the Shia branch of Islam. There are millions of Ismailis spread around the world in at least thirty countries including India, Pakistan, China, Tanzania, Uganda, Kenya, Syria, UAE, Tajikistan, Afghanistan, UK, USA, and Canada. In keeping with the Shia tradition, they are led by a hereditary Imam who is a direct descendant of the Prophet Mohammed, currently Prince Karim Al-Husseini Aga Khan, or better known as, Aga Khan IV.