Volume 42 of the Polish Wings series. In the early stages of the Second World War, the medium-sized twin-engine Vickers Wellington bomber was considered the real workhorse of RAF Bomber Command. Between 1939 and 1942, alongside the Handley Page Hampden and the Armstrong Whitworth Whitley, it was primarily the Wellington that bore the brunt of the RAF's increasing bombing raids against the Third Reich. This type was also used in Coastal Command units in the fight against U-boats and enemy ships and was used extensively for training RAF bomber crews. Production continued until October 1945, with a total of 11,462 aircraft built. The Wellington also became the backbone of all four Polish bomber squadrons 300, 301, 304 and 305 as well as the OTU training facilities where Polish crews acquired their combat skills. This volume of the Polish Wings series presents the history of the Vickers Wellington bombers in versions Ic and II in service with the Polish Air Force in exile between 1940 and 1942. The first part covers Squadrons No. 300 and 301 as well as the 18 OTU, while the second part describes the combat missions of Squadrons No. 304 and 305.