The United Kingdom ends combat operations in the Iraq War.
- The UK's military operation in Iraq will officially end at midnight, after the Royal Navy completes its training of Iraqi sailors.
- Tony Blair appears at the Iraq Inquiry and is questioned in public for the first time about his decision to take the United Kingdom to war against Iraq.
- A report about the United Kingdom's involvement in the Iraq War is released. The chairman of the inquiry, Sir John Chilcot, said that the invasion was not a "last resort" and was based on "flawed intelligence and assessments". The inquiry was announced on 15 June 2009 by then-Prime Minister Gordon Brown. The final hearing was held on 2 February 2011.
- More than a dozen alleged ISIS-linked, terrorist members of Rawti Shax, a European offshoot of the Iraqi Kurdish jihadist network Ansar al-Islam, are arrested in a coordinated, multi-nation sweep by police across Europe. The operation dismantled an integrated cell in Italy, the United Kingdom, Norway, Finland, Switzerland, and Germany. The group is accused of radicalizing fighters, planning attacks targeting Norwegian and British diplomats in the Middle East, and planning to establish a caliphate in Iraq's Kurdistan region.
- The United Kingdom raises its terror threat level from "substantial" to "severe" in response to conflicts in Iraq and Syria.