Fireships served in the Royal Navy over a period of several centuries. The earliest fireships – ships filled with combustible and flammable materials and explosives and sent into lines of enemy ships to attempt to set them on fire – were small merchant vessels deployed in large fleet actions, such as by Sir Francis Drake against the Spanish Armada at the Battle of Gravelines in 1588. Fire was a major hazard on the wooden warships of the time, which carried large quantities of flammable and explosive materials into battle. Both sides used fireships in a number of engagements during the Anglo–Spanish War, with varying levels of effectiveness. Fireships reappeared in unconventional forms during the English Civil War, and were used in earnest during the Anglo-Dutch Wars, particularly to great