Places: St. George's Tower, Oxford Castle

In a scene worthy of Game of Thrones, the Empress Matilda, mother of Henry II and acknowledged Queen Cersei of her day, is besieged in Oxford Castle, which is about to fall to the forces of her cousin and rival for the English crown, Stephen of Blois in 1141.  As his forces close in, Matilda makes a dramatic escape, being let down by ropes from the window of St. George's tower and escaping across the frozen river in a driving snow.  For greater dramatic effect as well as camouflage, she and her retinue of knights were dressed in white to blend in better with the weather.

Well, not quite.

The above story presumes that Oxford Castle, complete with its tower, high walls and fortified battlements, was the same in Matilda's time as it is now.  Disappointingly, it wasn't.  What is now the site of Oxford castle was claimed in 1071 by a Norman baron named Robert D'Oyly.  D'Oyly was part of William the Conqueror's invasion fleet.  He saw the site, which was already home to a Saxon ring fort and a chapel, and decided to take it for himself.  He began to build a stone church, with a proper castle along the motte and bailey format.  Only he didn't have his fortress built of solid stone, like the Castle today.  The battlements were constructed of gravel mixed with clay to make a rude cement.  The keep was made of wood.  It was this castle which Matilda holed up in during the period in English history known as the Anarchy, while she and Stephen fought for the crown to a lawless stalemate.  And, yes, she was besieged in the castle and had to make a run for it.  But it's likely that she left by one of the gates in the dead of night, not being lowered down the wall.  And, as for the white clothing and all that, probably not.

The present St. George's tower, built from coral rag stone, dates from about 1270, during the reign of Matilda's descendants, the Plantagenet Kings of England.  Over time, the clay and gravel battlements and wooden keep of the castle gave way to stone as successive lords and kings continued to bring the castle up to date with then-existing military understanding about defensive works.  In time, the castle fell into disuse and disrepair, being used off and on as a jail.  By the time of the English Civil War, the castle was almost a ruin.  But it became the Royalist capital and, in 1642, withstood another siege from Puritan forces.  It's re-use as a fortress was short-lived and it reverted to its role as a prison, one of the worst in England and frequently cited by reformers as an example of the need for prison reform. 

Finally, in 1954, the site was taken over by the National Trust to be preserved as an historical site.  The prison closed down in 1996.  A hotel now operates on part of the former prison site.