Early modern warfare is the era of warfare following medieval warfare. It is associated with the start of the widespread use of gunpowder and the development of suitable weapons to use the explosive, including artillery and firearms; for this reason the era is also referred to as the age of gunpowder warfare (a concept introduced by Michael Roberts in the 1950s). This entire period is contained within the Age of Sail, which characteristic dominated the era's naval tactics, including the use of gunpowder in naval artillery.