It is a curious fact that each of Martinů’s odd-numbered symphonies was preceded by a period when he found it difficult to compose with his customary speed and fluency. The First Symphony had been held up by his concern that he was ‘insufficiently prepared’ for it, and by the unsettled circumstances surrounding his recent escape to the United States. The Third was preceded by several months during which he composed little and was assailed by feelings of homesickness. The Fifth (H310), composed between March and May 1946, likewise arose from an interval dominated by depression and anxiety about the future. The euphoria expressed so radiantly by the Fourth Symphony appears almost to have vanished. The aftermath of the War was slow to bring the blessings for which he so fervently hoped. Chief among them was, of course, the prospect of returning permanently to Czechoslovakia, which he had not seen since his last holiday there in 1938. He voiced his hopes in his very first communication home after the restoration of postal services – a telegram to his brother František dated 27 June 1945 – less than a fortnight after the completion of the Fourth Symphony:

His hopes were raised further in September 1945 when the Prague Conservatoire offered him its Professorship of Composition. It may have seemed an ironic gesture from the establishment which had expelled him as a student, but nonetheless, Martinů accepted the offer with alacrity. For a while, his letters home spoke of his return as a near-certainty, but as time went on with no word of confirmation from Prague, his tone became ever more bitter and frustrated, as this extract from a letter to his family, dated Christmas Eve 1945, demonstrates: