Thomas was served heir to his father October 5, 1621 and heir portioner to his maternal grandfather on May 4, 1630 [or it was his son Thomas who was heir portioner]. He married twice and there were three sons by the second marriage: Thomas, James and Robert.
Source: Robert Halliday Lidderdale, An Account of the Lowland Scots Family of Lidderdale, 1950.
On the 30th March 1558, [Robert Richardson] was raised to be Lord Treasurer, and Master of the Mint. His progenitors for several generations were citizens of Edinburgh. His ambition was to accumulate money, and found a family, in which he succeeded. He purchased a great deal of land, and left it to his two sons, Sir James Richardson of Smeaton, and Sir Robert of Pencaitland, and his daughter Katherine, who married James Lidderdale.
[On the 7th July 1571, Mr Robert Richardson, commendatore of Sanct Marie Yle; James Richardsone, his sone naturall; James Lidderdiall, feuar of Sanct Marie, and several others, the list being headed by John, Lord Glammis, had lands, &c., forfeited. - (MS. Maitland Club, Edinburgh, 1833).]
We next learn that, on the 4th August 1572, the lands belonging to the priory were granted by charter to James Lidderdale, and Thomas his son in fee farm, by Robert Richardson, described as usufructuar, and William Rutherfurd, perpetual commendator, which the king confirmed on the 4th November 1573.
In May 1629 Thomas Lidderdaill had sasine [either the symbolic act of giving legal possession of heritable property, or the instrument by which such an act was proved to have happened] of the five pound land of Galeway.
[O]n the 25th October 1621, and 11th October 1627, Thomas Lidderdale, styled of St Mary, son of James Lidderdale, styled of Isle, had retour of Middle or Meikill Galtway. On the 4th May 1630, Thomas Lidderdaill de Sanct Mary Isle was heir parcener of Magistri Roberti Richardsone, commendatoris de Sanct Mary Ile, avi ex parte Matris. In December 1636, James Lidderdaill had sasine of Torris Grange (Torrs and Grange) and others. In December 1640, we find Thomas Lidderdaill of St Mary's Isle, and James his son.
Source: P.H. McKerlie, History of the Lands and Their Owners in Galloway, 1878.