“Underground Mosque” it is sometimes called. The Hacı Osmanoğulları Yeraltı Camii holds secrets beneath Istanbul. Let me share its captivating story.
The Hacı Osmanoğulları Yeraltı Camii, also known as Yeraltı Camii or Kurşunlu Mahzen, resides in Istanbul’s Beyoğlu district. Its origins trace back to a Byzantine fortress basement. Imagine this cellar transformed over centuries.
Initially, this space served as a crucial part of the city’s defenses. During the reign of Tiberios II in the late 6th century, the fortress was built to guard against Arab incursions. A massive chain blocked the Golden Horn’s entrance. This fortress secured one end of that chain.
After Constantinople’s conquest in 1453, the cellar became a storehouse. It held ammunition and served as a water cistern. Its transformation into a mosque occurred much later.
In the mid-18th century, Ottoman Vizier Köse Bahir Mustafa Pasha converted the cellar into the Hacı Osmanoğulları Yeraltı Camii. This act marked a significant change. The mosque’s prayer hall and main features are underground.
The 1754 Istanbul earthquake caused considerable damage. Sultan Mahmud I ordered the mosque’s reconstruction. It was completed in 1756. A minaret was added but later disappeared.
Inside the Hacı Osmanoğulları Yeraltı Camii, tombs honor significant figures. Two rooms contain cenotaphs attributed to Sahaba and Tabi’ al-Tabi’een. These additions came in 1753. A Naqshbandi dervish claimed a dream revealed the tombs’ presence.
One room holds cenotaphs for Amr ibn al-As and Wahb ibn Husayra. Tradition says they were captured during an attempted invasion. They were allegedly tortured to death. However historical accounts state Amr ibn al-As died in Egypt. There is little record of anyone named Wahb ibn Husayra.
The Hacı Osmanoğulları Yeraltı Camii also honors Sufyan ibn Uyaynah. He was a member of the Tabi’ al-Tabi’een. Local stories claim he was a soldier captured and martyred. Historical records show that Sufyan ibn Uyaynah died in Mecca.
The Hacı Osmanoğulları Yeraltı Camii’s structure is unique. Fifty-four columns support the roof’s vaults. Light enters through windows on the sea-facing wall. Above the mosque stands a building that once housed the Coastal Health Center.
An inscription above the entrance displays Sultan Mahmud I’s tughra. This is Istanbul’s oldest known tughra on a building. The mosque has a müezzin’s platform and two entrances. One entrance is on Kemankeş Caddesi. The other is on Karantina Street.
Today, the Hacı Osmanoğulları Yeraltı Camii remains an active place of worship. It is near the Karaköy ferry terminal. The Hacı Osmanoğulları Yeraltı Camii is a revered site in Istanbul. Many consider it second only to Eyüp Sultan in spiritual importance. Its blend of history and faith makes it a special place. A place where the past whispers to the present.