first. They sank of Italian shipping; half by one vessel, the submarine . It accounted for one Italian submarine, nine merchant vessels and one Motor Torpedo Boat (MTB). The loss of nine submarines and their trained crews and commanders was serious. Most of the losses were to mines. On 14 January 1941, U-class submarines arrived, and the submarine offensive began in earnest. One of the most famous Mediterranean submarines was , commanded for its entire career by Lieutenant-Commander Malcolm Wanklyn. He received the Victoria Cross for attacking a well-defended convoy on 25 May 1941 and sinking an Italian liner, the . In her 16-month operational career in the Mediterranean, before she was sunk in April 1942, Upholder carried out 24 patrols and sank around 119,000 tons of Axis ships – 3 U-boats, a destroyer, 15 transport ships with possibly a cruiser and another destroyer also sunk. On 8 September 1944, C-in-C Mediterranean ordered that the submarine base at La Maddalena be closed, and that Tenth Flotilla be disestablished and the submarines be incorporated into the First Submarine Flotilla at Malta. Cold War The submarine force was cut back after the end of the war. The first British nuclear-powered submarine, was launched in 1960, based around a U.S.-built nuclear reactor. This was complemented by the from 1966, which used a new British-built Rolls-Royce PWR1 reactor. The UK's strategic nuclear deterrent was transferred to the Royal Navy from the Royal Air Force at midnight on 30 June 1968, i.e. 1 July. The ballistic missile submarines (SSBNs) were introduced to carry out this role under the Polaris programme from 1968. These carried US-built UGM-27 Polaris A-3 missiles and were later replaced by the submarines and the Trident missile system from 1994. In 1978 the Flag Officer Submarines double-hatted as NATO Commander Submarine Force Eastern Atlantic (COMSUBEASTLANT) part of Allied Command Atlantic, moved from HMS Dolphin at Gosport to the Northwood Headquarters. made history in 1982 during the Falklands War when she became the first nuclear-powered submarine to sink a surface ship, the . HMS Splendid and HMS Spartan hunted the Argentine Navy carrier group Task Group 79.1 but did not engage. At the end of the Cold War in 1989 the Flag Officer Submarines, who was also COMSUBEASTLANT, a rear admiral, who , commanded a fleet of 30 submarines, which were grouped into four squadrons (First, Second, Third, and Tenth (SSBN)) at three