Marbeck's, a brick and timber building perched on the top of Windsor Castle's West wall, has a commanding view over the River Thames, Eton and the Western approaches to London. Built by the House of Lancaster during the reign of Henry V, (1413-1422) the house on this site was probably erected as part of St. George's College.

Half hidden behind the Horseshoe Cloisters, Marbeck's shares its courtyard with St. George's House and Chapel and the Chapter Library. The Chapter Library is presumed to be where William Shakespeare rehearsed and performed The Merry Wives of Windsor which was written for Queen Elizabeth I. This whole corner of the castle has been the site of houses and other buildings of St. George's College for over six hundred years, evidence of a thriving yet separate community within the castle.

Now a private residence, Marbeck's was named after John Marbeck, the organist for St. George's Chapel in 1541. He was also a composer and his was the first musical setting of the new liturgy in English. In 1543, Marbeck, with three other men, fell victim to a heresy hunt in Windsor and was condemned to death. While the others were all burned at the stake, Marbeck was reprieved by the intervention of influential friends.