Marines, also known as a marine corps and naval infantry, are an infantry force that specializes in the support of naval and army operations on land and at sea, as well as the execution of their own operations. In the majority of countries, the marine force is part of the navy, but it can also be under the army like the Troupes de marine (French Marines) and Givati Brigade (Israeli Marines), or form an independent armed service branch like the United States Marine Corps and Royal Marines.
Historically, tasks undertaken by marines have included providing protection from war while at sea, reflecting the pressed nature of the ships' company and the risk of mutiny. Other tasks would include boarding of vessels during combat or capture of prize ships and providing manpower for raiding ashore in support of the naval objectives.
With the industrialization of warfare in the 20th century the scale of landing operations increased; this brought with it an increased likelihood of opposition and a need for co-ordination of various military elements. Marine forces evolved to specialize in the skills and capabilities required for amphibious warfare.