Sanabad was a village where the palace of Humayd ibn Qahtaba was located in the early 3rd century AH. When Harun al-Rashid died, he was buried in this palace. A few years later, during the caliphate of al-Ma'mun, in 202 AH, Ali al-Rida, who was on his way to Baghdad was poisoned in the house of the emir of Sanabad, and al-Ma'mun buried his body near Harun's grave. From then on, that spot was called "Mashhad al-Rida" , or Mashhad(place of martyrdom)[1] for short.[2][3] The city developed around the grave of al-Rida as the holiest site in Iran for the Shia.[4]
Gradually, many pilgrims were attracted to this place, and their number increased year by year.[5]
