By coutesy of IRIB

Imam Musa Sadr, was born in Qom, Iran in 1928 to the prominent Sadr family of theologians. His father was Ayatollah Sadr al-Din Sadr, while Ayatollah Muhammad Baqir al-Sadr was his cousin. He attended his primary school in his hometown and then moved to the Iranian capital Tehran where he got in 1956 a degree in Economy from Tehran University. Then he moved back to Qom to study theology. He then edited some magazines in Qom. Eventually he left Qom for Najaf to study theology. His teachers were Imam Khomeini (Rh), Ayatollah Sayed Muhsin al-Hakim, Abul Qasim Khui, Ayatollah Boroujerdi, and Allameh Tabatabaei.

Imam Musa Sadr was an Iranian philosopher and a prominent Shi'ite religious leader who spent many years of his life in Lebanon as a religious and political leader.

The Sadr family was originally from Lebanon, and in 1960 Musa al-Sadr accepted an invitation to become the leading Shi'ite figure in the city of Tyre. Imam Musa Sadr quickly became one of the most prominent advocates for the Shi'ite population of Lebanon, a group that was both economically and politically disadvantaged. He was a vocal opponent of Zionist regime. In 1969 he was elected as the first head of the "Supreme Islamic Shi'ite Council", an entity meant to give the Shi'ites more say in government. In 1974 he founded the Movement of the Disinherited to press for better economic and social conditions for the Shi'ites. He established a number of schools and medical clinics throughout southern Lebanon, many of which are still in operation today.

He is most famous for his political role, but he was also a philosopher who had been trained by Allameh Tabatabaei. As Professor Seyyed Hossein Nasr said: "His great political influence and fame was enough for people to not consider his philosophical attitude, although he was a well-trained follower of long living intellectual tradition of Islamic Philosophy".

Imam Musa Sadr attempted to prevent the descent into violence that eventually led to the Lebanese Civil War, but was ineffective. In the war he at first aligned himself with the Lebanese National Movement. He had long good relations with the Syrians.

In August 1978,  Imam Musa Sadr and two companions departed for Libya to meet with officials from Qaddafi's government. He and his companions were never heard of again. It is widely believed that he was killed by Qaddafi, but the reason for this has never become known. Libya has consistently denied responsibility, claiming that Imam Musa Sadr and his companions left Libya for Italy. Some others have reported that Imam Musa Sadr remains secretly in jail in Libya. Imam Musa Sadr's disappearance continues to be a major dispute between Lebanon and Libya.

After his disappearance on August 31, 1978 Imam Musa Sadr became viewed as a martyr and as the spiritual leader of Lebanese Shi'ites. The Amal Party (Brigades of the Lebanese Resistance, the military wing of the Movement of the Disinherited) remains an important Shi'ite organization and looks to Imam Musa Sadr as its founder.

By the way, the life of such a figure like Imam Musa Sadr is so important for Islamic world. For this reason, some countries like Iran and Lebanon are also following the matter of  his disappearance and most of the Muslims and non-Muslims are waiting for his return. 
 
http://www.muslimherald.com/muslimherald/ms27.2/15412834.htm

http://www.imamsadr.ir