"Like other branches of Islam, Shia Islam is based on the teachings of the Quran and the message of .... Muhammad. In contrast to other types, the Shia believe that only God has the right to choose a representative to safeguard Islam, the Quran and sharia. Thus the Shias look to Ali, Muhammad's son-in-law, whom they consider divinely appointed, as the rightful successor to Muhammad, and the first omam. The Shia extend this belief to Muhammad's family, the Ahl al-Bayt ("the People of the House"), and certain individuals among his descendants, known as imams, who have special spiritual and political authority over the community" ....."modern Shia Islam is divided into three main branches. The largest Shia sect in the early 21st century is the Ithna ashariyya, commonly referred to in English as the Twelvers, while smaller branches include the Ismaili ("Seveners") and Zaidi ("Fivers")" .... "Shia Muslims consider sites associated with Muhammad, his family members (Ahl al-Bayt) and descendants (including the Shia Imams), their companions, and the prophets as holy places" (Wiki)