Twelver

Twelver, also called Ithna'ashariyya, is the largest branch of Shia Islam. It holds that twelve divinely appointed Imams succeeded the Prophet Muhammad in spiritual and temporal leadership, from Ali ibn Abi Talib to Muhammad al-Mahdi, who is believed to be in occultation and will reappear as the guided redeemer.

Imams are regarded as rightful, infallible guides who transmit sacred knowledge and interpret revelation. The twelve are: Ali, Hasan, Husayn, Ali Zayn al-Abidin, Muhammad al-Baqir, Ja'far al-Sadiq, Musa al-Kadhim, Ali al-Ridha, Muhammad al-Taqi, Ali al-Naqi (Al-Hadi), Hasan al-Askari, and Muhammad al-Mahdi.

Core beliefs include Usul al-din: belief in God, divine justice, prophethood, Imamate, the Day of Resurrection, and divine guidance. Twelvers view the Imamate as a divinely conferred, ongoing leadership that guides practice and interpretation. After the 12th Imam's occultation in the 9th century, Shi’a communities await his return.

Practices align with the Five Pillars, with Shia-specific observances such as the mourning of Husayn's martyrdom during Muharram and Ashura. The legal tradition is Usuli, in which qualified jurists (marja' al-taqlid) issue rulings that believers may follow.

Geographically, Twelvers are the majority in Iran and have significant communities in Iraq, Azerbaijan, Lebanon, Bahrain, Pakistan, and India. The Twelver framework has shaped Shia theology, jurisprudence, and political developments across the Muslim world.