section_path: Main branches or denominations/Shia
section_name: Shia
paragraph_text: Shia
  
  Shia Islam, or Shi'ism, is the second-largest Muslim denomination. Shias, or Shiites, maintain that Muhammad's successor as leader, must be from certain descendants of Muhammad's family known as the Ahl al-Bayt and those leaders, referred to as Imams, have additional spiritual authority. Shias are guided by the Ja'fari school of jurisprudence.
  
  According to both Sunni and Shia Muslims, a significant event took place at Ghadir Khumm during Muhammad's return from his final pilgrimage to Mecca, where he stopped thousands of Muslims in the midday heat. Muhammad appointed his cousin Ali as the executor of his last will and testament, as well as his Wali (authority). Shias recognize that Muhammad designated Ali as his successor (khalīfa) and Imam (spiritual and political leader) after him, but was prevented from succeeding Muhammad as the leader of the Muslims because of some other companions who selected Abū Bakr as caliph. Sunnis, instead believe that Muhammad did not appoint a successor before his death and consider Abū Bakr to be the first rightful caliph after Muhammad. Shias state the community deliberately ignored Ali's nomination, citing Umar's appointment by Abu Bakr, other historical evidence, and the Qur'an's stance that majority does not imply legitimacy.
  
  Some of the first Shia Imams are revered by all Shia and Sunnis Muslims, such as Ali and Husayn. Twelvers, the largest Shia branch and most influential, believe in Twelve Imams, the last of whom went into occultation to return one day. They recognize that the prophecy of the Twelve Imams has been foretold in the Hadith of the Twelve Successors which is recorded by both Sunni and Shia sources. Zaidism rejects special powers of Imams and are sometimes considered a 'fifth school' of Sunni Islam rather than a Shia denomination. They differed with other Shias over the status of the fifth imam and are sometimes known as "Fivers". The Isma'ilis split with the Twelvers over who was the seventh Imam and have further fragmented into more groups over the status of successive Imams, with the largest group being the Nizaris.
  
  For Shias, the Imam Ali Shrine in Najaf, the Imam Husayn Shrine in Karbala, and the Fatima Masumeh Shrine in Qom are also among the Islamic Holy sites.