On a bicycle ride through Oxford a few days ago, I encountered the traditional cluster of tourists snapping away with their cameras and iPhones around the ‘Bridge of Sighs’ in New College Lane. Being produced were yet more images of an iconic structure that is already to be seen in many thousands, perhaps millions, of photographic albums across the world, maybe with their owners’ arms outstretched as if to support it, rather as sightseers do with the Leaning Tower of Pisa.

As the visitors parted to permit my progress, I glanced up at the bridge and noticed, for the first time, that it bore a stone plaque commemorating the date of its construction, 1913. So this is its centennial year. In truth, I had been dimly aware of this; it had been mentioned when Pembroke College’s new bridge over Brewer Street opened earlier in the year that this was the first such link between parts of a college divided by a road since that built for Hertford exactly a century before.

Like much else that is good to look at in Oxford (the Examination Schools, the Boys’ High School in George Street, Brasenose College’s High Street frontage) the bridge was the work of architect Sir Thomas Jackson. Though there was strong opposition to its construction — principally from New College, whose bell tower was to be partly obscured from view by it — the finished bridge was widely admired. It is known as the Bridge of Sighs after Antonio Contino’s Ponte dei Sospiri in Venice, though its model was obviously the Rialto, which crosses the Grand Canal.

The architect says little about it in his Recollections, edited and arranged for publication in 2003 by his grandson, the organist and composer Sir Nicholas Jackson, an honorary fellow of Hertford. Jackson merely noted: “This disastrous year [1914, when the First World War started] began pleasantly enough. In January, Lady St Helier opened my new bridge at Hertford College, which she had given in memory of her husband.”

Lord St Helier, a leading judge, had died nine years earlier. He became one of the first new fellows of Hertford following its refounding in 1874, having played a key role in the dealings with banker T.C. Baring whose generosity made this possible.

Lady St Helier, a Dame Commander of the Order of the British Empire in her own right, had a very clear idea of her worth, describing herself in Who’s Who as “indefatigable in service of the poor and in Society . . . famed for her brilliant art of entertaining”.

Her claim was obviously justified, though, for it was at her table in 1908 that Winston Churchill sat next to, and became infatuated with, his wife-to-be, Clementine Hozier. Churchill’s biographer Roy Jenkins noted that the other guests included the legendary parliamentarian and wit F. E. Smith; the First Lord of the Admiralty, Lord Tweedmouth; and the American heiress Ruth Moore, who supplied much of the money that her husband, Lord Lee of Fareham, was later to spend on the restoration of Chequers as a home for British prime ministers.

Lady St Helier was also a close friend of the wealthy American novelist and social arbiter Edith Wharton, who writes in her autobiography A Backward Glance: “She took a frank and indefatigable interest in celebrities, and was determined to have them all at her house.” She wrote most amusingly, too, of “the cannibal chief who, on the point of consigning a captive explorer to the pot, snatched him back to safety with the exclamation: ‘But I think I’ve met you at Lady St Helier’s.’”

Speaking of funny stories, a number are to be found in the latest edition of Hertford College News, which celebrates the centenary of the bridge with an essay about it by history tutor Dr Christopher Tyerman and some recollections by former students.

I particularly enjoyed the contribution of Hugh Nicklin: “When I was up 1961-4 a jolly jape was played on someone. He had gone out for the evening, and while he was out some people placed the the contents of his bedroom on the walkway over the bridge, so that as he came home he found his bedroom just as he had left it, but 50 metres closer than he expected.”

Jimmy Hartley recalled: “On Guy Fawkes Night 1953 and 1954, I stood on the bridge armed with a soda syphon which I sprayed liberally on the students unlucky enough to be at other colleges that had no such prominent feature.”

What an admirable vantage point one has from the bridge was obvious to me when I made my first crossing a day or so back in the company of Hertford’s hospitable home bursar, Dr Andrew Beaumont. A surprise was to find it so much bigger than it looks from below.

The bridge is built in Clipsham stone, as are the Examination Schools. Jackson wrote of it in the Hertford College Magazine of May 1914: “A bridge of this kind in England is unusual, and naturally invites criticism. There are many examples in Italy, which contain useful suggestions, though I have tried to give the design a character rather in conformity with the traditions of the English Renaissance.”

Hertford is hosting a day of celebration for the bridge centenary for college members and guests on Saturday, September 28. Attractions of an evening party — besides “cocktail bar, Pimm’s and local beers” — include a performance by the Rick Hutton Band led by the rock’n’roller brother of Will Hutton, the Principal of Hertford for the past two years.