ANNE Bonny is a gentleman's daughter, but she is no lady. Mary Read has spent her life disguised as her deceased brother to avoid scandal. When their worlds collide on board Calico Jack Rackham's pirate ship, these two unlikely friends become a fearsome duo.

Freedom must come at a price, however, as told in Crossed Swords, a new play for York Footlights Theatre by York writer Olivia Jayne Newton, who co-directs next month's premiere with producer and cast member Daniel Wilmot.

Based on a true story, Newton's seafaring drama will run at the Upstage Centre Theatre, 41 Monkgate, York, from July 8 to 12 at 7.30pm nightly plus a 2.30pm Sunday matinee.

Presented in association with Baron Productions, Crossed Swords promises swashbuckling action, roaring sea-shanties and a stellar cast of York talent. "This incredible true story has to be seen to believed," says Olivia, who will play the lead role of Anne Bonny.

Further roles will go to Natalie Brimicombe as Mary Read; Daniel Wilmot as Calico Jack Rackham; Lee Gemmell, Captain Jonathan Barnet; John R Morgan, Governor Woodes Rodgers; and James Tyler, James Bonny. Richard Thirlwall will play pirate Sam Kendrick; Samuel Valentine, Rackham's First Mate, Henry Smythe; Gemma Shelton and BethanyAnne Middleton, Wenches; and Julia Morgan, Cabin Boy.

Inspiration for Olivia's play came from encountering folk big band Bellowhead at the Galtres Festival. "A friend dragged me along to see them – I'd never heard of them – but they sang this sea shanty and it made me think 'Pirates!'. So I started looking at stories of pirates and came across the story of Anne Bonny and Mary Read," she says. "What drew me to their story was that they were ahead of their time.

"It was featured in a documentary on YouTube and I was really intrigued. I found there'd been a play about them at the Royal Shakespeare Company in the 1970s and there's a reference to them in the 2013 video game Assassin's Creed IV: Black Flag – which shows my addiction to gaming! In a nutshell, Mary's story is about survival, whereas Anne is more rebellious."

Anne was the illegitimate daughter of an Irish gentleman and his chambermaid and was first passed off as a boy. "By the time she was heading to America she was very rebellious; she'd already killed one of her servants with a kitchen knife when she was 13 and that was just the start," says Olivia.

Disowned by her father, Anne married in America, moved to Jamaica with her husband, who became a small-time pirate, leaving her to her own devices as she roamed around the taverns.

"It was there that she met Calico Jack Rackham, a very flamboyant pirate captain, the very closest you could get to being like Johnny Depp's 'Captain' Jack Sparrow in the Pirates Of The Caribbean films," says Olivia. "In fact, I think Johnny Depp's character was based on him."

Anne duly eloped with Calico Jack. "Reports of the time say she was the most violent of all the crew, and she was also said to be very beautiful with her flaming red hair, almost like Boudica," says Olivia.

Mary was an illegitimate child too, who lived in disguise, dressed as her dead brother Mark to enable her mother to keep extracting money from her grandmother. Take up her story later and she has resumed the guise of a man on a pirate ship that wants to knock Calico Jack off his perch.

Left as the last one standing, she is asked to jump ship to join Jack's crew, and it is at this point that Anne and Mary bond. "They became the Thelma And Louise of piracy," says Olivia.

"Mary went on to die in prison of natural causes after being imprisoned for piracy, but no-one knows what happened to Anne after Mary died, so we leave it open ended as we want the audience to make their own mind up."

Plenty of cast members will play instruments in the July production. "We'll bring the play into the 21st century with modern language but there'll be traditional, period dress and traditional sea shanties and folk songs," says Olivia, who will handle guitar, Irish harp and lrish whistle, as well as sing, write the script and co-direct.

Tickets are available at £10 or £8 online at ticketsource.co.uk/crossedswords and proceeds will go to York Mind. Please note, Crossed Swords contains strong language and moderate adult themes and is suitable for age 12 and over. Visit the York Footlights website to view the show's trailer.