There have always been trends in popular fiction and literature. Trench coated private eyes were all the rage back in the 1930s and 1940s, and confessional pseudo biographies (often fictional), detailing harrowing childhoods topped the best seller lists of the past few years.

Such trends are just as common in genre fiction as they are in popular fiction. In recent years, the most popular fantasy novels are not Tolkien like tales of knights and their elfish companions, but urban fantasy novels featuring werewolves, vampires, modern cities, and strong Buffy like lead characters.

Science Fiction does not escape the popular trend. I've always been a fan of time travel stories in fiction, but until recent years there was very little of it around. Golden Age writers such as Isaac Asimov and Robert Heinlein ventured into the sub genre in their heyday, as did a small number of literary authors such as Kurt Vonnegut and Daphne du Maurier. But it has only been in the past 15 years that time travel fiction has come into its own.

H.G.Wells published The Time Machine in 1895, and for the next one hundred years there were fewer than fifty novels published where time travel was central to the story. But since 1995, fifty six new time travel novels have been written, turning what was once seen as a quirky plot device into an entire sub genre of science fiction.

Modern writers such as Connie Willis and Eric Flint have lifted the time travel story to a whole new level, introducing their own sub genres within sub genres. Lovers of time travel fiction can now choose between traditional 'stuck in the past' novels such as Doomsday Book by Connie Willis, alternate universe time travel stories written by S.M. Stirling or John Birmingham, or romance novels set between past and present such as the Outlander series by the ever popular Diana Gabaldon.

These writers now regularly top the best seller lists and line up for science fiction awards, and their fans build communities online, in many cases writing new stories set in the same universe. An example of this is Eric Flint's Grantville series, where fans are actively encouraged to write new stories about the twentieth century American town transported to seventeenth century Germany, with the best stories being published in the Grantville Gazette.

Recent examples of the genre include the Island in the Sea of Time trilogy by S.M. Stirling, in which the island of Nantucket is mysteriously transported back in time by three and a half thousand years, The Plot to Save Socrates, by Paul Levinson, where two time travelers attempt to prevent the death of Socrates, The Anubis Gates, by Tim Powers, in which a twentieth century academic travels back to nineteenth century London to do battle with ancient Egyptian sorcerers, and the ever popular and award winning The Time Traveler's Wife, by Audrey Niffenegger, demonstrating that time travel in fiction is now very much mainstream.

There has never been a better time for fans of time travel novels.