Battle of the Afsluitdijk

The Battle of the Afsluitdijk of 12–14 May 1940 was an unsuccessful attempt by German Wehrmacht forces to seize the Afsluitdijk during the invasion of the Netherlands. German invasion plans called for a simultaneous attack on Vesting Holland from multiple directions, expecting to capture the country's capital and most important region in a day's time.

To facilitate an attack from the north, Wehrmacht elements commanded by General Kurt Feldt first needed to cross the Afsluitdijk, a 32-kilometer-long (20 mi) causeway and dike connecting the country's northern provinces to its western province of North Holland and ultimately to Amsterdam and beyond.

Despite finding themselves outmanned and outgunned, Royal Dutch Army troops commanded by Captain Christiaan Boers, under the overall command of rear-Admiral Hoyte Jolles, managed to successfully hold back the attackers at Fort Kornwerderzand, protected by modernized heavily fortified defensive positions. The German Army was thus prevented from immediately concentrating its full strength on the country's most vital area.

The pinned down German forces were eventually forced to retreat and subsequently routed their attack across the IJsselmeer, bypassing the Afsluitdijk and landing north of Amsterdam. The Dutch garrison capitulated on May 14, after the bombing of Rotterdam. Kornwerderzand was the only line of defense that successfully withstood an enemy attack during the conflict, and was one of the few Blitzkrieg defeats suffered by the Wehrmacht.