It took one conversation in the pub about Templar Knights and the Crusades and Robyn Young knew she was hooked.

The stories behind the historical events fascinated the 31-year-old Hove author so much she decided to do her research and write a fictional tale from the perspective of the characters involved in the bloody battle between Christians and Muslims.

It took seven years for Robyn to finish Brethren, the first in a trilogy of novels, but her hard work has paid off as the book is in the best-seller lists in the UK and US.

She said: "I became intrigued by the idea of Templar Knights. The name sounded evocative. I started studying the subject and realised how much of a story they had.

"It took six months to a year to feel I was able to start writing. The book is in the third person which enables me to go into the minds of the different characters and to write an overview of the battles.

"When I started writing I was doing creative writing at the University of Sussex and it really helped because it meant I could bounce my ideas off other people."

It was while she was at Sussex that Robyn met her agent and she said his advice has been invaluable.

She said: "Becoming a novelist is like going for a walk along a series of hills. You get to the top and you realise there's another hill to climb.

"Researching the book was hard work. I ended up doing things like drawing maps so I could work out where everything was.

"I think what gives my book originality is that it's told from the Christian and Muslim point of view.

"I actually found the Muslim side easier to write about because the person I was writing about had been a true person in history.

In the West my main protagonist is fictional."

Robyn is in the process of writing the second book in the trilogy, Crusade, and hopes to have it finished by Christmas. It will be released in summer 2007 and the final novel in 2008.

Translation rights to Brethren have been sold to publishers in France, Germany, Greece, Italy, Poland, Portugal, Russia, Spain, Sweden and Bulgaria.

Robyn says she never imagined the book would do so well.

She said: "It is a very competitive world and it is a very hard world to get into.

"The most invaluable thing to me is working with other writers and allowing them to critique my work. It is important because writing can be so isolating.

"My grandfather was my biggest inspiration because he used to tell us all sorts of stories when we were younger.

"You also need to have that determination and not give up at the first rejection."

Brethren is published by Hodder and Stoughton and is available in all bookshops. For more information visit www.robynyoung.com