John P Ravilious gave the following summary. [1]
1.5.1a.2 Robert de la Hay
Death: bef 8 Jan 1448[9]rector of Brantingham, co. Yorks.
'Robertum del Hay filium meum', beneficiary and executor of the will of his father Peter de la Hay, dated 8 Aug 1426 (proved 11 Apr 1431) [Test. Ebor. II:11-12[9]])
named in the will of his brother Thomas [Test. Ebor. II:11, note[9]]
cf. Test. Ebor.II:11, notes[9]
9. "Testamenta Eboracensia [A Selection of Wills from the Registry at York]," The Surtees Society, Durham: Andrews & Co., Part II (Vol. 30, Surtees Society publications), pp. 11-12 will of Peter de la Hay, proved 11 Apr 1431.
[1] Genealogy Medieval, [URL].