Many tales have been told of ghosts wandering the Castle. Betsa Marsh, writing in a British Heritage Magazine article said:
"The Red Room has spooked so many people that the owners called in an Edinburgh priest to exorcise its lingering spirits. Legend says that a young servant girl bore an illegitimate Borthwick son in the room. Mother and baby, potential threats to the title, were quickly put to the sword. In another era, the Borthwick family chancellor used this room, and the niches for his safes remain in the stone wall to this day. According to gossip, the Borthwicks discovered their chancellor was embezzling money from the family coffers. Eschewing the nicety of a performance review, they intercepted the chancellor on his way home from Edinburgh one evening and cancelled his contract by burning him to death. The ghosts of the young servant girl and the fired chancellor still wander the stony spiral staircases of Borthwick, some people say, and even the most stalwart visitors admit to feeling invisible presences in the Great Hall."
The twin towered fortress of Borthwick Castle was built in 1430 by the first Lord Borthwick, whose sepulchre can still be seen with that of his Lady in the old village church. A charter to build the Castle was awarded to Sir William de Borthwick by King James I in thanks for his part in bringing the King home to Scotland after 18 years imprisonment in England.
The Castle was built as a stronghold capable of withstanding attack from invaders, particularly the English. It was also a base from which offensive action could be launched when needed. The stone used was of the finest quality, with 100 feet walls, 20 feet thick at the base and originally had a moat, drawbridge and portcullis.
It was also a home to the Borthwicks, where lavish entertaining took place in the impressive Great Hall. You can still see the magnificent canopied fireplace 20 feet (6m) high and 15 feet (4.5m) wide to the right of which is a "sedile" - a seat of honour for the master of the house enriched with a carved canopy and a shield bearing the Borthwick Arms.
The Castle played host to many distinguished guests and Mary Queen of Scots enjoyed the hospitality of the Sixth Lord Borthwick on many occasions, including her honeymoon. So inevitably she and her third husband the Earl of Bothwell sought sanctuary at Borthwick in 1567 when they learned that the Scottish nobles (who were suspicious of Bothwell’s influence on Mary) planned to capture them. A force of 1,000 men surrounded the castle but Mary escaped through a window in the Great Hall dressed as a pageboy, and rode through the night after her husband.
In 1650 Oliver Cromwell laid siege to the Castle and delivered the following letter to the ninth Lord Borthwick, on 18 November 1650:
"Sir - I thought fit to send this trumpet to you, to let you know, that if you please to walk away with your company, and deliver the House to such as I shall send to receive it, you shall have liberty to carry off your arms and goods and such other necessaries as you have.
You have harboured such parties in your house as have basely and inhumanly murdered our men, if you necessitate me to bend my cannon against you, you may expect what I doubt you will not be pleased with. I expect your present Answer, and rest your servant.
Lord Borthwick did not respond immediately, but after bombardment by cannon which destroyed the east parapet and tore a large cavity in the stonework, he came to terms with Cromwell, leaving the castle with his wife and child and moveable goods. The scars on the stonework can still be seen today and a copy of Cromwell's original letter hangs in the Great Hall.
When Cromwell's forces left the Castle it lay derelict for many years. In 1813 the stones in the Great Hall fireplace were dislodged by a tree growing through. The Borthwick family removed the tree and restored the chimney breast and then in 1903 the Great Hall's woodwork was renewed.
During World War II the Castle was considered strong enough to store Scottish Public Records as well as treasures from the National Library and the Royal Museums of Scotland
Since then, the castle has been treated with more respect. Helen Bailey, who leased the castle from the Borthwick family, brought it up to its current genteel standards and lovingly and authentically restored their ancestral home before handing it on to the present owners. In the early 1970s, electricity and central heating were added and the Castle has been operating as a hotel since 1973.