Martyrdom of imam Ja'far al-Sadiq is an important religious and public holiday in Iran.
It is celebrated on the twenty-fifth day of the month of Shawwal.
Al-Sadiq is the last person to be recognized as an imam by all Shiite sects.
Shia Islam is the state religion of the Islamic Republic of Iran.
Ja'far ibn Muhammad al-Sadiq, commonly known as simply al-Sadiq (the Truthful), was the sixth Shite imam, i.e. rightful spiritual and political successor to Prophet Muhammad.
He inherited the position of imam from his father Muhammad al-Baquir.
Ja'far al-Sadiq died in 765 (148 AH).
He was poisoned by the Abbasid caliph al-Mansur, who sent him poisoned fruit.
Imam al-Sadiq was buried in Medina next to his grandfather Zayn al-Abidin and father Muhammad al-Baquir.