During the civil war in the 1640s the Castle was occupied by Moss Troopers but in November 1650 they were forced to surrender to Oliver Cromwell's army under the command of General Monk who bombarded the ramparts into the ruin we see today. After the reinstatement of the Stewarts, Charles II awarded the land to Sir John Nisbet, King's Advocate in 1663. Later the estate fell to William Nisbet Hamilton using the surname of his parents. He abandoned the castle and built the mansion house at Archerfield. The estate then passed through marriage to the Nisbet Hamilton-Ogilvy family whose executors sold it to Jackson Russell in 1922 and then to farmer George Mitchell for £34,000 before the Duke of Hamilton purchased the land in 1962. Dirleton Castle is maintained by Historic Scotland and is open to the public.

Local historian David Berry writes, the island of Fidra is made up of the North and South Dogs (related to the German'dogge' and our 'dog' as a follower or companion) are skerries off the main island and are never connected to the main island at any state of tide. The larger South Dog continues as a treacherous ridge towards Eyebroughy and means boats must stand well out when coming round the SW corner. The smaller North Dog lies under the lighthouse and is almost submerged at spring full tide. The part to the SE that is separated from Fidra proper at high tide is Castle Tarbert (from the gaelic Tarbeairt, an isthmus or portage). Eilbotle (from the Anglian for 'old settlement') was on the nearby shore, which is why the wood has that name.

Only a stave keep, the later chapel and perhaps some small buildings were on the island itself. Just who lived here is a fascinating conundrum because after the Goddodin fell in the 7th century, this must have been a no-man's-land among Angle, Pict, Brython and Viking, with Fidra an important outpost on the coastal sea-routes (easy to get to, big enough to be comfortable & support some livestock, hard to assault). There are stories of 'the race of Congals (from Congalton?) being slaughtered here by Vikings in the 9th century and the hill in Yellowcraig wood was probably another stave fort but less secure that Tarbert. However, no serious archaeology has been done to substantiate any of this. What fascinates me is the mix of origins of local place-names from all their languages, which must mean they all settled--you don't get your name for a place into use just by passing through.

The whole place would have been moved bodily to the present Dirleton when John de Vaux (from Rouen) was given the lands there in the reign of Malcolm IV (1153-1165). He was Steward to Alexander II's household and gifted the now-surplus island and adjoining poorer land to Dryburgh around 1220. Dirleton was built in the mid-1200's. The St Nicholas chapel is therefore probably a later element from this time and the place was almost certainly not referred to as 'Eilbotle'