The first 'Ashura mourning and Ghadir festival in Baghdad

Al-Suyuti, in "History of the Caliphs", reports that the Shi'a in Baghdad wrote in 351 AH on the doors of the mosques a curse on Mu'awiya, a curse on whoever seized Fatima's Fadak, on whoever prevented al-Hasan from being buried beside his grandfather, and on whoever banished Abu Dharr. It was wiped off at night. ²

Mu'izz al-Dawla wanted to restore what had been written, but the vizier al-Muhallabi advised him to write in place of what had been wiped out the phrase "God curse the wrongdoers against the family of the Messenger of God". Al-Suyuti says that they openly cursed Mu'awiya alone. ²

In 352 AH, on the day of Ashura, Mu'izz al-Dawla required the people to close the markets and forbade the cooks from cooking. Domes were raised in the markets and sackcloth hung on them, and women went out wailing and holding mourning over al-Husayn. Al-Suyuti says that it was the first day on which he was mourned in Baghdad, and describes it as an innovation that lasted for years. ²

On the eighteenth of Dhu al-Hijja of the same year the festival of Ghadir Khumm was held and the drums were beaten. ²

The description here is in al-Suyuti's text and from his viewpoint. The academic account and the account of the Shi'i sources have not yet been added. An additional source is needed.