1636 : the Ottoman onslaught
(Book)

Too many enemies . . . too few allies. The modern West Virginia town of Grantville has been displaced in time to continental Europe in 1632. Now four years have passed. The long-feared attack on Austria by the Ottoman Empire has begun. Armed with new weapons inspired by the time-displaced Americans of Grantville, the Turks are determined to do what they were unable to do in the universe the Americans came from - capture Vienna. An this time they won't have to face massive reinforcements from Austria's allies. But, they will still have to face general Mike Stearns, late of the good ol' U.S. of A.