Shia Muslims in Iran and other countries are celebrating Eid al-Ghadir, the most important festive occasion on the Islamic calendar. Eid al-Ghadir marks the anniversary of the day when Prophet Muhammad (PBUH) named his cousin and son-in-law, Ali ibn Abi Talib, as his successor and the head of the Muslim community. Imam Ali, the first Shia Imam, was appointed by Prophet Muhammad at a location in the vicinity of the ...