The Istanbul-class frigates (also known as TF-100, MILGEM II, ðstif and I class) are a group of ten multirole frigates currently being constructed for the Turkish Naval Forces and the Indonesian Navy. Developed under the MILGEM national warship program as the I-class frigate, the Istanbul class is an enlarged version of the anti-submarine corvette, with enhanced endurance and MiDLAS vertical launching system (VLS) for multi-role capability.
On 19 January 2017, the Turkish Navy held a ceremonial steel cut for the lead ship TCG Istanbul (F 515). Istanbul was laid down on 3 July 2017 and launched on 23 January 2021.
The Istanbul class has its origins in the Turkish MILGEM project for developing national warships and warship building industry. The program calls for the construction of a warship family in three classes, where all vessels would be designed with high degree of commonality. The first product of the project emerged as the Ada-class anti-submarine/patrol corvette. The Istanbul class, originally known as the TF-100 class under the MILGEM-G designation, belongs to the second development phase, where the structure of the Ada class corvette is extended to host multi-role capabilities.
The Istanbuls have the guns, self protection and anti-submarine warfare systems of the Ada-class. but with twice the number of anti-ship missiles and will be equipped with the indigenous MDAS vertical launching system.
The first ship of the class, TCG Istanbul, was laid down on 19 January 2017. The fifth and largest modern warship to be both indigenously designed and built in Turkey under the MILGEM program, it is claimed that more than 75% of its systems are of indigenous manufacture. Its steel cutting ceremony was attended by Turkish Defence Minister Fikri Ià Âñk and senior military officers, including Admiral Bülent BostanoÃÂlu, Commander of the Turkish Naval Forces.
Construction took six years and the vessel was commissioned into service on 19 January 2024.
At full load, the ship's maximum displacement ranges from 3,000 to 3,171 tonnes.
This plant includes one General Electric LM2500 gas turbine and two MTU diesel engines, which drive two propellers.
The ship is armed with 16 Atmaca anti-ship missiles and a 16-cell MðDLAS (National Vertical Launching System) for surface-to-air missiles like the HðSAR-D RF.
There is a bow 76 mm/62-caliber Super Rapid gun and a Aselsan GOKDENIZ 35 mm dual-barreled close-in weapon system (CIWS). The frigate also carries two twin 324 mm torpedo tubes for anti-submarine warfare.
Combat operations are managed by the network-centric ADVENT Combat Management System (CMS). The frigate is equipped with an electronic warfare system and an infrared detection and tracking system developed by the Turkish company Aselsan. Additional ship systems and software are supplied by Havelsan, along with components from various local subcontractors.
The aft section of the ship includes a flight deck and a hangar.
It was stated in Aselsan's 2023 Annual Report that the Istanbul-class frigate was exported to an unnamed Middle Eastern country.
Indonesian shipyard PAL Indonesia signed a memorandum of understanding with TAIS Shipyards on procuring the Istanbul-class frigate in June 2025. Minister of Defense of Indonesia, Sjafrie Sjamsoeddin, signed the procurement contract for two frigates on 26 July 2025. On 19 January 2026, during the DIMDEX 2026 expo in Doha, Qatar, TAIS Shipyards signed a US$1 billion agreement with Barzan Holdings of Qatar to supply TCG ðzmir and ðçel to the Indonesian Navy. Barzan Holdings will provide the loan to Indonesia for the acquisition of the frigates. Turkish media Defence Turk claimed that the export agreement is yet to be confirmed as there are issues which are "under negotiation".