A bridgehead (or bridge-head) is an area of ground on the enemy's side of a bridge, especially one that needs to be taken and defended in order to secure an advance.
Bridgeheads typically exist for only a few days, the invading forces either being thrown back or expanding the bridgehead to create a secure defensive lodgement area, before breaking out into open country – as happened when the U.S. 9th Armored Division seized the Ludendorff Bridge at Remagen in 1945 during World War II. In some cases, such as during the Gallipoli Campaign in World War I, a bridgehead may exist for months.
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