I think it was a novel, but not sure. Some people, from perhaps more than one period (I don't remember for sure) got swept back to the ancient Mediterranean. It's somehow hypothesized that they were drawn along in the time-transport-wake of some time traveler, and if they can cause something massively anachronistic, it'll get attention of the traveler, who can return them to their own times.
Some inventions like outfiting boats' bows with naval rams to turn the tide of a significant battle did the trick, I think.
I think the main character was a male from our time or so. I think one of the other characters was a priestess from Minoan Crete.
I think his would have been from the early 2000s at latest, but could be from 1990s or even decades earlier, if it's a book I picked up from a used book seller. Possibly it was even a novella, short story, or serialized novel in F&SF, Analog, Galaxy SF, or other magazine? I'm not sure.