They are the public faces of Cambridge colleges, the first to welcome new arrivals and the last to pace the courts at night checking all is well.

Now the Cambridge head porters, seen by many as the colleges’ unsung heroes, are stepping into the limelight in their own right as the stars of a new exhibition of portraits.

A striking full-length painting of Head Porter of Caius, Russell Holmes, is prominently featured in the show, which opens at The Pitt Building on Trumpington Street, Cambridge on Saturday, 18 June.

Artist Louise Riley-Smith, who painted the 25 portraits, was inspired to take up the project by her husband Jonathan, former Dixie Professor of Ecclesiastical History and fellow of Emmanuel. “My husband and I were chatting one day and he said why don’t you paint the head porters of the colleges?” she says. “I said, ‘What, all of them?’ That’s quite an undertaking.’ Then I thought, actually it would be such fun to do it.”

Three of the 31 college head porters politely turned down Louise’s invitation to sit for a portrait, but the rest enthusiastically agreed (three have been omitted simply because – with less than two years to complete the project and despite working “flat out” – the artist ran out of time).

She started each painting by chatting to her subject, observing them and deciding with them where and how they should be portrayed. While some porters are painted at their desks or behind counters in the Lodge, Russ is pictured in formal uniform of tails and top hat, leaning on a Caius umbrella. “Russ is a great character, very dapper, very jaunty,” says Louise. “I saw his medals and asked him about them, and he talked to me about his army life, so I painted him with them.

“He was very kind and helpful and carried my easel for me.”

Louise painted Russ in the Upper Library at Caius, where one of the large windows floods the room with the northern light she prefers, though she later added the College’s Gate of Honour as a background. “We did about three or four sessions of two hours at a time,” Russ recalls. “It wasn’t comfortable – after 25 minutes I had to say ‘I need a break’. One of my feet was going to sleep.”

There was no talking during the sessions, but Louise chatted to her subjects over cups of tea during breaks. She discouraged them from looking at their portraits while work was in progress, but Russ admits he “kept peeking”.

Head porters have “huge responsibility”, Louise, points out: ‘They have a large body of staff under them, they are looking after the students with all their emotional and other problems, they’re liaising with the Fellows, looking after health and safety. They do a fantastic job and are not really recognised.”

As a group, the porters were “very fatherly”, she adds. “They care about people very much and they’re good at interacting with people. One was in tears – he told me about a very special student who came back later and said ‘I couldn’t have done it if it hadn’t been for you’.

“They were wonderful – very obedient: they put up with me being very bossy and saying ‘I can’t talk now’.”

For Russ, the experience of seeing his painting dotted around Cambridge on signs advertising the exhibition has been a strange one. “I think ‘Is that really me?’ It’s surreal having your portrait done, because – a person like myself - you don’t expect anyone to be that interested in painting you. But it’s nice to see because I think she’s captured it quite well.”

*  Porters – an exhibition of portraits of the head porters of the colleges of Cambridge University, by Louise Riley-Smith, is at The Pitt Building, Trumpington Street, Cambridge from Saturday 18 - 25 June 2016, 10am-6pm. Entry is free.