The Type 45 destroyer, also known as the D or Daring class, is a class of six guided missile destroyers built for the United Kingdom's Royal Navy. The class is primarily designed for anti-aircraft and anti-missile warfare and is built around the PAAMS (Sea Viper) air-defence system utilizing the SAMPSON AESA and the S1850M long-range radars. The first three destroyers were assembled by BAE Systems Surface Fleet Solutions from partially prefabricated "blocks" built at different shipyards, the remaining three were built by BAE Systems Maritime – Naval Ships. The first ship in the Daring class, HMS Daring, was launched on 1 February 2006 and commissioned on 23 July 2009.^[16]

The Type 45 destroyers were built to replace the Type 42 (Sheffield class) destroyers that had served during the Falklands War, with the last Type 42 being decommissioned in 2013. The National Audit Office reported that, during an "intensive attack", a single Type 45 could simultaneously track, engage and destroy more targets than five Type 42 destroyers operating together.^[17] After the launch of Daring on 1 February 2006 Admiral Sir Alan West, a former First Sea Lord, stated that it would be the Royal Navy's most capable destroyer ever, as well as the world's best air-defence ship.^[18] The reduction in the number to be procured from twelve, then to (up to) eight, finally with only six confirmed (in 2008) was controversial.^[19][20]

Another controversy arose when it was revealed that due to a design flaw on the Northrop Grumman intercooler which, when attached to the Rolls-Royce WR-21 gas turbines and functioning in the warm climate of the Persian Gulf power availability was diminished considerably,^[21][22] and it quickly became apparent that the class was not operating as originally envisioned.^[23] A refit will take place from 2019-21 to fully resolve the problems with the six ships in the class.^[24]