Between 1941 and 1942, the concept of National Savings was introduced by the British government. Each region in the country was provided with a savings target to achieve. This was based on the region's population, with each general level of savings having a class of warship assigned. This became known as Warship Week, due to its similarities with War Weapons Week – which was a drive to replace the materiel lost at Dunkirk through a savings campaign.