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 -long 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 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". Nazi Germany invaded the Netherlands on 10 May 1940 as part of "Fall Gelb", simultaneously invading Belgium and France through the Ardennes. In the north, German forces rapidly advanced past two thin Dutch defensive lines parallel to the border, stretching across the provinces of Drenthe and Groningen, before further advancing into western Friesland. On 12 May, the German 1st Cavalry Division—later regrouped into the 24th Panzer Division—had captured the last line of Dutch defences lying in front of the Afsluitdijk, and began preparing an assault on two defensive lines comprising 17 pillboxes and casemates around Fort Kornwerderzand, designed to withstand direct hits by 210 mm rounds and indirect hits by 280 mm rounds. Its three main casemates were made of of reinforced concrete and sheltered 230 men, twenty-one 7.92 mm "Schwarzlose" machine guns, three 50 mm guns, and a 50 mm shore-based naval gun, with similar defences at the Afsluitdijk's other end.