Direct proof of use
UK Ministry of Defence strike logs directly document RAF Brimstone use in the war against the Islamic State. On December 7, 2015, Tornado GR4 aircraft supporting Iraqi forces near Ramadi engaged an Islamic State mortar position with a Brimstone missile, and on December 8 Tornados conducted two Brimstone attacks west of Qayyara.
The same official reporting series records repeated Brimstone employment in 2016, including attacks on mobile cranes and cave entrances in January, an Islamic State vehicle in northern Iraq and an oilfield engineering vehicle in Syria in February, and fighting positions, a truck bomb, and a light machine-gun position in June.
Sources: RAF Air Strikes December 2015, RAF Air Strikes January 2016, RAF Air Strikes February 2016, RAF Air Strikes June 2016
Timeline
The earliest detailed public MOD entries in this record are from December 2015, after the UK Parliament authorized strikes in Syria and RAF operations continued over Iraq. Those reports show Brimstone used for close air support in Iraq before the monthly logs began recording Syrian Brimstone strikes against oilfield-repair and mobility equipment in January and February 2016.
By October 2018, RAF Tornados and Typhoons were supporting the Syrian Democratic Forces around the Hajin pocket in eastern Syria; MOD reporting said Tornados used Brimstone against a truck bomb blocking an SDF advance and that RAF aircraft later used Paveway IVs and a Brimstone missile against mortar positions and a weapons stockpile near Hajin. In February 2019, the MOD reported the first operational firing of Brimstone 2 from a Typhoon FGR4, against a boat used by Daesh south of Baghuz Fawqani.
Sources: RAF Air Strikes December 2015, RAF Air Strikes October 2018, RAF Typhoons Use Brimstone
Narrative
Brimstone appeared in this conflict as a British coalition air-launched precision weapon, not as Islamic State equipment. The documented users were RAF Tornado GR4 crews during the main Tornado phase of Operation Shader and RAF Typhoon FGR4 crews after Brimstone integration moved onto Typhoon under Project Centurion.
The strike logs show a varied target set rather than a single anti-tank mission. Brimstone was used against mortar teams, vehicles, checkpoints, cave entrances, fighting positions, truck bombs, engineering equipment, mobile cranes, and a boat. The supported ground forces named in the official releases included Iraqi forces, Kurdish forces, moderate Syrian opposition fighters, and the Syrian Democratic Forces.
The MOD's 2019 Typhoon release links the Brimstone 2 firing to the final territorial campaign against Islamic State in eastern Syria, when the SDF were clearing the remaining pocket around the Euphrates. That use extended Brimstone's role from Tornado-carried close air support and interdiction into the RAF's post-Tornado Typhoon strike package.
Sources: RAF Air Strikes February 2016, RAF Air Strikes October 2018, RAF Typhoons Use Brimstone, Improved Brimstone Enters Service