He had two sons James and David, and was the last effective Lidderdale Laird of St. Mary's Isle.

The succession of Lidderdale lairds of St. Mary's Isle, as given, is from a genealogical deduction made by James Lorrimer, Lyon Clerk, on January 30, 1851. It is from James to Thomas to James ob. 1665 to Robert to Thomas ob. 1687. This correction has to be made, it passed once from one brother to another and should proceed thus James to Thomas, to Thomas, who d.s.p., to his brother James to his son Robert to his son Thomas ob. 1687.

On the walls of the family burial enclosure in Galtway Kirkyard are tablets to the memory of the following members of the family mostly buried there.

HIC JACIT TO
MAS LIDDER
DAILLE SANCTO
INSULO MAR
DOMINUS QUI
OB
DECIMO DIE FEB
AETATIS 7

and underneath has been added

Here lies David Lidde
rdale of Torrs son to
the above Thomas who
died 21st Apl 1732 Aetat 57

Only the "7" is decipherable of Thomas's age. The Coat of Arms is carved on the tomb, with the motto, without difference, as Thomas was the undoubted head of the family.

The tomb is mentioned in the report of the Royal Commission on Historical Monuments of Scotland, paragraph 260, p. 142. It points out that the lower part of the tomb has been pared away for David's inscription and the photo confirms it. There is no border or bordure on the shield.

Source: Robert Halliday Lidderdale, An Account of the Lowland Scots Family of Lidderdale, 1950.

For a more detailed discussion of Thomas Lidderdale and the loss of St. Mary's Isle, refer to Lidderdale of Isle, so called Persecutor is Robert Halliday Lidderdale's Early History of the Lidderdales.

The other parish joined to Kirkcudbright, about 1683, was Galtway. It is in the centre of the present parish. The site of the ancient church is two miles from Kirkcudbright. Several years ago the walls could be traced, and the building was only thirty feet by fifteen. It is believed that a priory also stood in this old parish (Galtway), but we cannot find any trace of the site, which, however, is not to be wondered at, when the ancient buildings were so long used in lieu of quarries. The burial ground of the Lidderdales is here, within the walls. On an altar tomb, surmounted by the arms, there is a Latin inscription in quaint old lettering, to the following effect : - "Here lies Thomas Lidderdale, of St Mary's Isle, who died 1st February 1687, aged fifty-seven." Also another - "Here lies David Lidderdale of Torrs, son to the above Thomas, who died 21st September 1732, aged fifty-seven."

St. Mary's Isle appears to have been retained by the Lidderdales. On the 23rd June 1668, Robert, son of James Lidderdale, had retour of the two and a-half merk land of the Isle. In July 1668, Thomas Lidderdale of Gerantoun, son of Robert, had sasine of the land of St. Marie Ile; and on the same day Robert Lidderdale, now of St. Marie Ile, had sasine of the same.

In 1681, Thomas Lidderdale, along with Grierson of Lag, held one of the grievous courts at Kirkcudbright, against the Presbyterians. In 1683, he held another court in Twynholm in a severe and overbearing manner.

On the 12th February 1698, James was served heir to his father Thomas Lidderdale of Sanct Mary Isle.

In December [1669] Thomas Lidderdale had sasine of the ten merk land of Torrs, etc. On the 18th of the same month and year, James Lidderdale had principal sasine of the two and a-half merk land of St. Mary's Isle. On the same date, in liferent, Margaret Brown and Robert Lidderdale, her children in fie, had principal sasine of the ten merk land of Torrs, etc. Probably she was the wife of Thomas Lidderdale, who died in February 1687. He is stated to have had issue:

James

David, born 1675, of Torss, who married Eleanora, eldest daughter of Sir James Dunbar of Muchrum, and had issue. He died 21st September 1732.

On the 12th February 1698, James was served heir to his father Thomas Lidderdale of Sanct Mary Isle.

Source: P.H. McKerlie, History of the Lands and Their Owners in Galloway, 1878.

Extracts from M. McL., Harper, Rambles in Galloway, Chapter 6 - Dundrennan to Kirkcudbright, 1876 (http://www.old-kirkcudbright.net/rambles/rambles1.htm).

The Prior of St. Mary's Isle, like other priors, had a seat in Parliament. Robert Strivelin was the last prior, and after his death Robert Richardson, who also held the offices of Lord Treasurer and Master of the Moat, was presented to the Priory on 30th March 1538. He sat as Commendator in the Parliament of 1560. In 1572, Mr. Robert Richardson, Usufructuary, and William Rutherford, Commendator, granted to James Lidderdale, and Thomas, his son, the lands which belonged to the Priory. This grant was confirmed by a charter from the king, dated the 4th November 1573.

The Priory was connected with the ancient parish of Galta, or Galtway, now united with the parish of Kirkcudbright. Galtway churchyard is situated about two miles from Kirkcudbright, in a quiet sequestered sunny spot, surrounded by trees. In it there is a monument to the memory of Thomas Lidderdale of St. Mary's Isle, on which is the following inscription:

Hic. Jacet. THOMAS Lidderdale Sancte Insulae. Mariae. Dominus. qu. obt.
11. Decimo. Die. Feby. anno 1687. etais 57.

Also

Here lies DAVID Lidderdale of Torrs, son to the above THOMAS, who died
21 April 1732, aged 57.