In 1391 he was appointed Master Forester at Pontefract Castle, and in that year accompanied Bolingbroke to the siege of Vilnius.
He remained in these posts despite Richard II's confiscation of Bolingbroke's estates after the death of John of Gaunt in 1399.
In June of that year Waterton was among the first of Bolingbroke's retainers to join him at Ravenspur, where he arrived with two hundred foresters,[2] although according to a speech by the Earl of Northumberland in Shakespeare's Richard II (Act II, scene i), Waterton was among those who sailed with Bolingbroke from the continent:[6][7] Then thus: I have from Port le Blanc, a bay In Brittany, received intelligence That Harry Duke of Hereford, Rainold Lord Cobham, That late broke from the Duke of Exeter, His brother, Archbishop late of Canterbury, Sir Thomas Erpingham, Sir John Ramston, Sir John Norbery, Sir Robert Waterton and Francis Quoint, All these well furnish'd by the Duke of Bretagne With eight tall ships, three thousand men of war, Are making hither with all due expedience And shortly mean to touch our northern shore.
Bolingbroke was crowned as Henry IV on 13 October 1399, and on 20 November Waterton was appointed his Master of Horse.
On 28 November 1399 he was granted the manor of Doubledyke in Gosberton, Lincolnshire which had been forfeited by Sir John Bushy or Bussy.
Waterton then marched with Henry IV's army against Northumberland at Newcastle upon Tyne, and was later sent to arrest both Hotspur's widow and son.
Northumberland imprisoned him at Warkworth Castle on 6 May, but released him in June, his place as prisoner being taken by his brother, John Waterton.
[2] Waterton acquired considerable property, including a grant in 1412 from Henry IV's second wife, Joan of Navarre, of a manor at Healaugh which had formerly belonged to the Percys.
His arms, displayed on his alabaster effigial monument, were Barry of six, Ermine and Gules, over all three crescents sable.
1408), was knighted in 1434 and was High Sheriff of Yorkshire in 1441, married firstly, Jane, daughter of John Meeres of Kirton-in-Lindsey, Lincs., by whom he had a son Sir Thomas Waterton.