Craigmillar Castle is simply one of the most completely preserved medieval castles in Scotland.
Craigmillar began life as the tower house that still forms the core of the castle. This was constructed around 1400, probably by Sir George Preston, one of a line of Prestons who played a large part in civic life in Edinburgh over several hundred years.
It was his grandson Sir William Preston who, in the 1440s, was responsible for Craigmillar's most notable feature. He added the curtain wall that surrounds the tower house on three sides and creates the inner courtyard. In about 1510 Sir Simon Preston added a further layer of enclosure, erecting outer walls to form the outer yard and east and west gardens.
Craigmillar Castle was captured by the English in May 1544 with its laird (another) Sir Simon Preston, who was also Provost of Edinburgh at the time. A programme of rebuilding in the 1550s included the construction of a new range of buildings along the east side of the inner courtyard. This was designed to provide more modern and spacious accommodation than was available in the tower house.
It was probably in this new east range that Mary Queen of Scots stayed in September 1563 and again in December 1566. It was during her second stay that conspirators agreed the "Craigmillar Bond": the plot to kill Mary'sdissolute husband Lord Darnley.
In 1660 the Prestons sold Craigmillar Castle to Sir John Gilmour. Craigmillar saw another round of building, this time leading to the creation of the west range. In the early 1700s the Gilmours did what other landed families across Scotland were doing at the same time. Rather than trying to convert their castle into a residence suitable for Edinburgh high society of the day they abandoned it. They moved instead to Inch House, newly built in what later became Gilmerton, named after the family.
Craigmillar Castle became overgrown and ruinous over the following two centuries, and was passed into state care in 1946. Today it is cared for by Historic Scotland.
Links: www.undiscoveredscotland.co.uk, en.wikipedia.org