The earliest mention of the name Alkmaar is in a 10th-century document. As the village grew into a town, it was granted city rightsin 1254. The oldest part of Alkmaar lies on an ancient sand bank that afforded some protection from the sea during medieval times. Even so, it is only a couple of metres above the surrounding region, which consists of some of the oldest polders in existence.
In 1573 the city successfully withstood a siege by Spanish forces under the leadership ofFernando Álvarez de Toledo, 3rd Duke of Alba. It was a turning point in the Eighty Years War and gave rise to the expression Bij Alkmaar begint de victorie ("Victory begins at Alkmaar"). The event is still celebrated every year in Alkmaar on October 8, the day the siege ended.
In 1799, during the French revolutionary wars, an Anglo-Russian expeditionary force captured the city but was ultimately defeated in the Battle of Castricum. The French victory was commemorated on the Arc de Triomphe in Paris as Alkmaer.
The North Holland Canal, opened in 1824, was dug through Alkmaar. In 1865 and 1867 the railways between Alkmaar and Den Helder and between Alkmaar and Haarlem were built respectively.
In the second half of the 20th century, Alkmaar expanded quickly with development of new neighbourhoods. On October 1, 1972, the town of Oudorp and the southern portions of Koedijk and Sint Pancras were added to the municipality of Alkmaar
