On 4 July 1943, an RAF Liberator crashed soon after take-off at Gibraltar airport, killing General Wladyslaw Sikorski, Prime Minister of the Polish Government in Exile and Commander-in-Chief of the Polish Armed Forces. For Gibraltar, this disaster caused a short-lived crisis, which soon passed. But for the Government in Exile it started a slide in its reputation and influence, from which it never recovered. And in the wider setting, it can be seen as an indicator of the changing balance of power within the wartime Allied Coalition. / The Gibraltar Disaster spawned a mass of conspiracy theories. Many people refused to accept that it had been an accident, proposing instead that the General had been assassinated on the orders either of Churchill, or of Stalin, or even of the General's own subordinates.
Gibraltar played a vital role in Allied operations in the Mediterranean theatre and the disaster coincided very closely with the start of the nearby Italian Campaign, within which the Polish Second Corps would win its laurels at the Battle of Monte Cassino. Yet the slow progress of the Western allies in Italy was to reveal serious deficiencies in their overall strategy.
The Disaster also coincided almost exactly with the onset on the Eastern Front of the titanic and decisive Battle of Kursk. At Kursk and in subsequent operations, the Red Army achieved results which the Western Allies were never able to match, giving notice of Stalin's political dominance in Europe, which would follow. The inexorable rise of Soviet political power in Allied counsels was the chief cause of the subsequent demise of Polish influence.
In the first phase of the War, 1939-41, Poland had been one of Britain's key allies. The outstanding performance of Polish squadrons, for example, tipped the balance during the Battle of Britain. In the second phase, 1941-43, the picture changed dramatically with the entry both of the USSR and the USA. In the final phase, beginning in the summer of 1943, Britain's relative position and that of her original allies gradually faded. The Gibraltar Disaster was a clear marker of the changing circumstances.