Expeditionary warfare is the deployment of a state's military to fight abroad, especially away from established bases. Expeditionary forces were in part the antecedent of the modern concept of Rapid Deployment Forces. Traditionally, expeditionary forces were essentially self-sustaining with an organic logistics capability and with a full array of supporting arms.
The earliest examples of expeditionary warfare come from the Sea Peoples, a term used for a confederation of seafaring raiders of the second millennium BC who sailed into the eastern shores of the Mediterranean, caused political unrest, and attempted to enter or control Egyptian territory during the late 19th dynasty, and especially during Year 8 of Ramesses III of the 20th Dynasty.
The raiding tactics were expanded into the more complex expeditionary warfare operations by Alexander the Great who used naval vessels for both troop transporting and logistics in his campaigns against the Persian Empire.
The next exponents of expeditionary warfare in the ancient world of the Mediterranean Basin were the Carthaginians who introduced two entirely new dimensions to the use of naval forces by staging not only operations that combined naval and land troops, but also eventuated in combining strategic multi-national forces during the land phase of the operation when Hannibal in his most famous achievement at the outbreak of the Second Punic War marched an army, which included war elephants, from Iberia over the Pyrenees and the Alps into northern Italy.