Typically, how many artillery decks were in the sailing ships of the line?
The first English two-decker was built in 1514. In the middle of the 18th century, larger three- or even four-deckers with 98 to 140 guns were built, that served as admirals' command ships. Those have however proven highly unstable and difficult to manouvre, so large two-deckers were more common as the most practical ones.