This gentle, affectionate drawing of the square in front of the Corn Exchange off High Street, Old Town, may look like the work of a local artist, but in fact it’s anything but.

This scene was captured in the summer of 1947, when the country was still recovering from the second global conflict in a century that thought it had already seen the war to end all wars. If you have eagle eyes, you may be able to see that the film of the week is God is My Co-Pilot, a 1945 American black-and-white biographical war film from Warner Bros.

Aged 59 when the Second World War broke out, our artist, one Randolph Schwabe, might have been expected to have had a quiet war. Yet in September 1939 his life was also turned upside down in its own way. Schwabe held the prestigious post of Principal of the Slade School of Art in London, and as such was responsible for ensuring that his colleagues and students decamp from its London base to the city of Oxford when war broke out, to share premises with the Ruskin Drawing School.

A talented artist as well as a high-flying academic, Schwabe took commissions from many of the leading intellectuals and patrons of his day. He had a great talent for recording, which may have been born in his role as an official war artist during the First World War, when he produced illustrations of the work done by the Women’s Land Army.

Since 1930 he had also kept a detailed diary, both chronicling national and international events as tension grew in Europe, and elegantly observing the lives of his fellow artists and academics. An influential and genial scholar, he was close to many of the great and good of his time, and he is widely considered the Pepys of the art world. The Diaries of Randolph Schwabe, edited by Gill Clarke, makes compulsive reading for anyone interested in the mid-20th century art world – or indeed the mid-20th century itself. And it is these diaries that we have to thank when we are pinpointing the provenance of this drawing.

Swindon’s first Corn Exchange was built as, yes, a place to store and sell corn, in 1852, but soon it doubled up as our first Town Hall and Magistrate’s Court, and simply couldn’t cope. In 1866 a larger, grander building was completed, with a 80 foot clock tower and elegant arcades. However, across the Atlantic, the US wheat prairies were expanding, shipping costs were falling, and by 1880 UK corn prices had plummeted. The Corn Exchange became a skating rink and a cinema, but the square outside it was still regarded as a significant piece of public realm that graced the original Old Town.

On Sunday, July 20, 1947, Schwabe, who had by now moved back to London, took the train to Swindon to begin a commissioned drawing of that square. He stayed with a friend in Aldbourne, but records “I made a routine of getting to Swindon about 10.35 by bus and leaving about 6.35, also bus; working about 6 hours each day”.

By Thursday, July 24, he had attracted the attention of a local businessman. “The wine merchants in the Square at Swindon, whose premises figure in my drawing, were very pressing that I should do another portrait of their building, but I declined… I had a glass of excellent sherry with them,” he reports. On Saturday, July 26, he left Swindon, his work complete – and on the Monday is dismayed at the week’s pile of letters that has accumulated in his Slade office – “a day’s work…”

Poignantly, just 14 months later, Schwabe died of heart disease.

The Corn Exchange morphed once more, into the Locarno Dance Hall in 1952, hosting bingo, wrestling matches and concerts by the likes of the Yardbirds and the Small Faces. It closed in 1984, and now little more than its façade still stands. This drawing of it is of course a delight in its own right. But perhaps what makes it particularly interesting is that it captures a tiny slice of a world that is on the brink of yet more enormous change.

The Diaries of Randolph Schwabe, British Art 1930-48, edited by Gill Clarke.