Roger de Quincey, the Earl of Winchester (called also as 'Winton' for short), gave the canons of Dryburgh 'a toft in villa de Hadinton', which became, St. Laurence House.  The later chapel, dedicated to St. Laurence and which belonged to the mother-church of St. Mary's in Haddington, was rated at 5 merks. The patronage of this chapel belonged to the nuns of Haddington, and the village or hamlet about a mile west from the burgh, now goes by the name of St. Laurence, where the Estate and chapel stood.

In the year 1532, the old Convent of Saint Catherine of Sciennes (Sienna) in Edinburgh got an accession of territory in the lands of St Laurence House, however, the pious Sisters however did not long enjoy the benefits of their East Lothian estate as St Laurence House was shortly afterwards 'brent and desolated' by the Earl of Hertford, better known as the Duke of Somerset, along with 'Hadington towne the freres and nunry'.

The lands of St. Laurence house came into the hands of the Seton's, during the time of George, 7th Lord Seton, and passed to his 3rd son, Sir John Seton, 1st of Barnes and to his Estate. In the 5th generation of Seton ownership, after the death of the fourth Earl of Dunfermline on 26th December 1694, the representation of the Dunfermline family appears to have devolved upon Sir John Seton of Barns, great-grandson of Sir John Seton 1st of Barns and the immediate elder brother of the celebrated Chancellor Seton.

Sir John's son, George Seton of Barnes, who, in 1704, was served heir of his grandfather (also George Seton of Barnes), married Anne, daughter of Sir George Suttie of Balgone, and sold the lands of Barnes to the celebrated Colonel Charteris, in 1715. However in a bond dated 29th June 1727, he is described as "George Seton, late of Barns, alias Lord Dumfermling;" and from then on through 1737/38, where he appears to have resided at his house of St. Laurence on his lands in Haddington, until his death.