The Islamic Development Bank (IsDB) is a multilateral development financing institution located in Jeddah

Jeddah

Jeddah, Jiddah, Jidda, or Jedda is a city located on the coast of the Red Sea and is the major urban center of western Saudi Arabia. It is the largest city in Makkah Province, the largest sea port on the Red Sea, and the second largest city in Saudi Arabia after the capital city, Riyadh. The...

, Saudi Arabia

Saudi Arabia

The Kingdom of Saudi Arabia , commonly known in British English as Saudi Arabia and in Arabic as as-Sa‘ūdiyyah , is the largest state in Western Asia by land area, constituting the bulk of the Arabian Peninsula, and the second-largest in the Arab World...

. It was founded by the first conference of Finance Ministers of the Organisation of the Islamic Conference (OIC, now the Organisation of Islamic Cooperation), convened 23 Dhu'l Qa'dah 1393 AH
(18 December 1973).
The bank officially began its activities on 15 Shawwal

Shawwal

Shawwāl is the tenth month of the lunar Islamic calendar. Shawwāl means to ‘lift or carry’; so named because she-camels normally would be carrying a fetus at this time of year.-Fasting during Shawwāl:...

 1395 AH (20 October 1975).