After graduating from the RSAMD in 1998, Peter worked for over a decade in children's theatre and theatre-in-education. Primarily devising and performing issue-based dramas in schools and community venues throughout the UK.

During this time he developed a close working relationship with Little Fish Theatre Company in London with whom he performed a number of forum theatre plays on issues ranging from racism and homophobia to knife crime and cyberbullying.

One of which, a forum theatre play about homophobic bullying in schools entitled "Them & Us: Whose Side Are You On?", he adapted for a tour of Edinburgh schools after receiving £6500 funding from LGBT Youth Scotland, Healthy Respect and Edinburgh City Council’s Community Safety Department.

The Scottish premiere of which was at the The Assembly Rooms in Edinburgh.

In the early noughties, Peter worked with Tim Lince, artisitic director of Pendle Productions and its sister company The Storytellers Theatre Company, on a number of productions.

These included pantomimes, musicals and two-hander adaptations of classic novels in which he played a variety of lead roles including Jim Hawkins in Treasure Island and James in a musical adaptation of James and the Giant Peach.

For several years, Peter worked exclusively with Garry Stewart and Baldy Bane Theatre Company in Glasgow. First as an actor and drama workshop leader, then as a writer and director

Productions included pantomines, short films and forum theatre plays. Notably Crush and Gold Stars & Dragon Marks, both of which explored issues of gender stereotyping and the effects of domestic abuse on children and young people.

Peter first worked with Cumbernauld Theatre over 20 years ago when he toured secondary schools in North Lanarkshire with a series of monolgues and duologues from Macbeth in which he played the lead and faciliated drama workshops on the key themes.

However it wasn't until 2011 before he made the transition from theatre-in-education to mainstream theatre, working closely with former artistic director Ed Robson on two consecutive Christmas shows: Cinderella and The Night Before Christmas, the latter of which was devised by the cast.

This was followed by The Street, a series of vignettes about Sauchiehall Street on a Saturday night, which was devised in collaboration with final year drama students from Motherwell College and formed part of a trilogy entitled Intimate Secrets.

The highlight, though, was a touring adaptation of Kidnapped in which he played the swaggering Jacobite Alan Breck Stewart. A performance described by The Scotsman as "Peter Callaghan captures perfectly the essence of the vainglorious, proud yet eminently likable outlaw."

Peter's first television role was that of a pizza delivery man in the BBC sitcom All Along The Watchtower directed by Lissa Evans.

Other credits include the wife-stealing mate of Burn Gorman in Zam Salim's BAFTA-winning comedy Up There, a mobility scooter salesman in an early episode of Still Game and a Spartacus-inspired office worker in the BBC Three sitcom How Not To Live Your Life.

He also featured in a couple of short films by David Goodall of Soundsmove: Crush, adapted from his theatre-in-education play of the same name; and Changed Days, an award-winning drama about dementia.

On the commercial front, he appeared in Not Ever, Scotland's first tv campaign aimed at tackling women-blaming attitudes to rape; and Alcohol: Don't Push It about peer pressure in pubs.

Peter's sole radio credit is Lieutenant Henry "Birdie" Bowers, Captain Robert Falcon Scott's ever-cheerful companion on his ill-fated Terra Nova expedition to the South Pole, in Stef Penney's two-part adaptation of Apsley Cherry-Garrard's memoir The Worst Journey In The World.

Directed by Kate McCall, with a specially composed score by Will Gregory of Goldfrapp, it has been repeated numerous times on BBC Radio 4 and BBC Radio 4 Extra.

He also recorded a number of promotional trailers for BBC Scotland including Strictly Come Dancing and Sports Personality of the Year.

As well as voice-overs for Pendle Productions' Muppets-style musical Out Of Africa, Red Kite Animations' pilot The Grimply Brothers and three verbatim monolgues for the University of Glasgow's research project Missing People, Missing Voices.

After appearing in a string of school shows at Graeme High School in Falkirk where he played Koko to future opera singer Cheryl Forbes' Katisha in The Mikado, Peter developed a fondness for musical theatre which continues to this day.

In 1997 he appeared in the RSAMD's 150th anniversary production of Into The Woods as the un-happy ever after Narrator. The following year he starred alongside Dawn Steele and Clare Waugh as the far-from-handy handyman Andy in The Steamie.

Other musical theatre credits include the title role in James And The Giant Peach in Pendle Productions' nationwide tour of schools, community venues and studio theatres.

And the twin roles of Abel The Gardener and Uncle Alan in Image Musical Theatre's touring production of Tom's Midnight Garden (see featured audio clip).