Iṣfahān (Persian: اصفهان, romanized: Esfahān, historically also rendered in English as Ispahan, Spahan, Sepahan, Esfahan or Hispahan and known in classical Arabic as Aṣbahān/أصبهان) is the third-largest city in Iran after Tehran and Mashhad, but was once one of the largest cities in the world, it is one of the ancient Persian cities and is known in Persian as Nesf-e Jahan, “Half the World”.
Iṣfahān was conquered at the end of year 20, during the reign of ‘Umar b. al-Khaṭṭāb (may Allah be pleased with him). Several reports mentioned that the Prophet’s (ﷺ) companion, Abū Mūsā al-Ash’arī (may Allah be pleased with him), took part in the conquest of the city. Other companions are cited as well.
Iṣfahān – like other major Persian Sunni cities – used to be one of the strongholds of Sunni Islam in Pre-Safavid Iran, it was a major source of Sunnī and ḥadīthist scholarship.

The Jāmeh Mosque of Isfahān or Jāme’ Mosque of Isfahān, also known as the Atiq Mosque (مسجد عتیق) and the Friday Mosque (مسجد جمعه), was the grand, congregational mosque (Jāmeh) of Isfahān city, within Isfahān Province, Iran. The mosque was built during the Umayyad dynasty. It is one of the oldest mosques still standing in Iran and one of the remnants of the Sunni heritage of Isfahan that has been vigorously violated by Twelver Shia rulers, starting with the (openly) anti-Sunni Shia Safavid dynasty (who desecrated the graves of Sunni scholars in Isfahan and beyond and removed the names of the Sahabah, particularly, Abu Bakr and ‘Umar from all ancient mosques) to the modern-day Khomeinist regime of Iran.