A monastic patron, he is remembered as the founder of Gisborough Priory in Yorkshire, England, in present-day Redcar and Cleveland, in 1119.

[citation needed] What is known clearly is that this Robert de Brus is first mentioned during the period 1094 and 1100, as a witness to a charter of Hugh, Earl of Chester, granting the church of Flamborough, Yorkshire, to Whitby Abbey.

Possibly the Earl of Chester in about 1100–1104 enfeoffed Robert of certain portions of his Cleveland fee in Lofthouse, Upleatham, Barwick, Ingleby, and other places.

In 1109 at a Council of all England held at Nottingham, he attested the charter of King Henry I confirming to the church of Durham certain possessions which the men of Northumberland had claimed.

[9] When David became king, he settled upon his military companion and friend the Lordship of Annandale, in 1124,[10] There is, however, scant evidence that this Robert ever took up residence on his Scottish estates.

[15] Evidence from charters involving Robert de Brus indicates that his wife Agnes was an heiress of the Surdeval family.

Her exact parentage is not known, she may have been an unrecorded daughter of Richard de Sourdeval, who held many manors in the Yorkshire region.

As the founder of Gisborough Priory, he was buried inside the church, in the place of honour between the Canon's stalls in the Quire.

Both the Scottish and English sides of the family would be laid to rest there, the last being Robert de Brus, Fifth Lord of Annandale in 1295.