| Unit Name: | No. 300 (Masovian) Squadron RAF |
| Dates: | 1 July 1940 – January 1947 |
| Country: | United Kingdom |
| Allegiance: |  Polish government-in-exile |
| Branch: | Royal Air Force |
| Role: | Bomber |
| Command Structure: | RAF Bomber Command |
| Nickname: | Masovian Mazowiecki |
| Equipment: | Fairey Battle |
| Equipment Label: | Aircraft |
| Battle Honours: | Millennium Offensive, bombing raids on V-weapons sites, D-Day, crossing the Rhine, Battle of the Ruhr, bombing of Hamburg and Battle of Berlin. |
| Notable Commanders: | Squadron Leader Bronisław Szota |
| Identification Symbol Label: | Squadron Badge heraldry |
| Identification Symbol 2: | BH (July 1940 – October 1946) |
| Identification Symbol 2 Label: | Squadron code |
No. 300 (Polish) Bomber Squadron "Land of Masovia" (Polish: 300 Dywizjon Bombowy "Ziemi Mazowieckiej"; also "No 300 (Masovian) Squadron") was a Polish bomber squadron formed in Great Britain as part of an agreement between the Polish government-in-exile and the United Kingdom in 1940. It was one of 15 squadrons of the Polish Air Force in exile that served alongside the Royal Air Force in World War II. It was disbanded in 1947. 300 Squadron is now represented by 300 (Isle of Axholme) Squadron of the Royal Air Force Air Training Corps, which made the alliance with the Polish Air Force is 1994.
Before the outbreak of World War II, the Polish government signed an agreement with the Royal Air Force. According to the appendix to the Polish-British Alliance, in the event of war with Germany, two Polish bomber squadrons were to be created on British soil. However, after Germany and the USSR invaded Poland, most of the Polish airmen who reached the West were incorporated into the Polish Air Forces being created in France. It was not until the fall of France that Polish airmen started to arrive in the United Kingdom in large numbers.
Polish evacuees and refugees with experience in aerial warfare were at first housed in a military camp in Eastchurch.
No. 300 Polish Bomber Squadron was created On 1 July 1940 as the first such Polish unit at RAF Bramcote, as a part of the Polish Air Forces in Great Britain. As there was a large number of Polish airmen, often with experience in combat against German forces in Poland and France, further bomber squadrons were created by 24 July.
Between 19 July 1940 and 8 May 1945, the crews of 300 squadron flew 3,891 sorties and spent 20,264 hours in the air.
At first equipped with Fairey Battle light bombers, the squadron was re-equipped with Vickers Wellington medium bombers on 16 November 1940. The squadron used several variants, including Mark IC, IV, III and X. In 1941 while the unit was equipped with Wellingtons and flying from Hemswell on "gardening" (mining) operations, the squadron's Intelligence Officer was Michael Bentine, later to become well-known as an entertainer. On 5 March 1944 the unit was re-equipped with Avro Lancaster heavy bombers. It was the only Polish squadron that operated Lancasters, and it continued to use them until the end of World War II (Mk I and Mk III variants).
During the war the squadron took part in most of the notable air offensives in Europe, including attacks on the Germany Kriegsmarine preparing for Operation Sea Lion, also ships such as the docked in Brest, France, other naval facilities in Wilhelmshaven and its U-boat facilities in Saint-Nazaire, Millennium Offensive on large bombing raids on Cologne, bombing raids on V-weapons sites, D-Day, in support of crossing the Rhine, the Battle of the Ruhr, the bombing of Hamburg, and the Battle of Berlin.
A number of the crew members were in late 1942 attached to the RAF Tempsford based No. 138 (Special) Squadron RAF as the newly formed Flight C operating the Handley Page Halifax.
The last mission was the bombing of Obersalzberg on 25 April 1945 against Adolf Hitler's residence in Berchtesgaden. The unit was disbanded in January 1947, after the Allies withdrew their support for the Polish government-in-exile.
| +Commanding officers of 300 squadron | |||
| From | Commanding officer | Notes | |
|---|---|---|---|
| 1 July 1940 | Lt.Col. engineer pilot Wacław Makowski | with W/Cdr K. P. Lewis as a British supervisor | |
| 18 July 1941 | Mjr pilot Stanisław Cwynar | ||
| 27 January 1942 | Mjr pilot Romuald Suliński | ||
| 1 August 1942 | Mjr pilot Władysław Dukszto | Since 9 July a co-commander | |
| 31 October 1942 | Mjr pilot Adam Kropiński | ||
| 4 May 1943 | Mjr pilot Mieczysław Kucharski | ||
| 18 November 1943 | Mjr pilot Kazimierz Kuzian | ||
| 18 January 1944 | Mjr pilot Adam Kowalczyk | ||
| 1 April 1944 | |||
| 2 February 1945 | Mjr pilot Bolesław Jarkowski | ||
| 17 September 1945 | Mjr pilot Romuald Suliński | ||
| 22 February 1946 | Mjr pilot Bolesław Jarkowski | Until the dissolution of the unit in January 1947 |
| +Bases from which 300 Squadron operated | |||
| From | To | Base | |
|---|---|---|---|
| 1 July 1940 | RAF Bramcote | ||
| 22 August 1940 | RAF Swinderby | ||
| 18 July 1941 | RAF Hemswell | ||
| 18 May 1942 | RAF Ingham | ||
| 31 January 1943 | RAF Hemswell | ||
| 22 June 1943 | RAF Ingham | ||
| 1 March 1944 | RAF Faldingworth |