Our clue as to his movements, for a short time, becomes one of surmise rather than of actual proof. At the dispersal of Buckingham's followers, Sir Robert and his attainted companions fled to Brittany, and he remained probably with them at Vannes or the neighbourhood, until the Earl of Richmond set out on his final expedition from Harfleur to Milford-Haven. This he doubtless accompanied, although no special mention is made of his name, nor as to his taking part in the engagement at Bosworth, where however he must have been present from circumstances that followed. Dugdale says "he was a successful sharer in the benefit of that great victory," another thing to that of sharing its danger. A much more important event however, identifying the presence of Sir Robert at Bosworth, or immediately near, and shewing the confidence the victor placed in him, was Richmond despatching the knight, the day after the battle, and before Henry left Leicester, with a detachment of horse to the castle of Sheriff-Hutton in Yorkshire, to convoy the unfortunate Earl of Warwick (son of the Duke of Clarence and nephew of Edward IV.), then a prisoner there, to the still safer and more dangerous custody of the Tower of London, only to emerge eventually from thence to his death on the scaffold. This mission is thus described by the old chronicler Hall. Henry in order "to obsist the first likely mischiefe, sent before his departure from Leycestre Sir Robert Willoghby knight to the maner of Sheryhutton in the County of Yorke for Edward Plantagenet Erle of Warwike sonne and heire to George Duke of Clarence then beyng of the age of xv yeres, whom Kyng Richard had kept there as a prisoner durynge the tyme of his vsurped reigne. Sir Robert Willoghby accordynge to hys commission receaved of the conestable of the castle the Erle Edward, and him conueighed to London, where the youngelynge borne to perpetual calamitie was incontynent in the towre of London putt under safe and sure custody."