Siege of Schenkenschans

The Siege of Schenkenschans (30 July 1635 – 30 April 1636) was one of the more important sieges of the Eighty Years' War. The capture of the strategically located fortress by the Spanish army of the Cardinal-Infante Ferdinand of Austria opened up the Dutch Republic to a possible invasion. The Dutch Stadtholder, Fredrick Henry had to pull out all stops to counter this strategic threat and recapture the fortress in an epic siege that lasted even through the winter months. He succeeded in doing so after nine months.

• http://en.wikipedia.org/wiki/Siege of Schenkenschans