However, he devoted his efforts to the art of Mercery rather than that of the Hatter, and transferred to the senior livery company: in 1435/36, he appeared before the Court of Aldermen and prayed to be admitted as a Mercer, a petition which was granted.

[16][17] This was before the present mansion built by Hobart arose: John Leland noted, "Syr Geffrey buildid a fair house of brike at ... in Northfolke.

[1] During a gathering in the City of the leaders of the Yorkist and Lancastrian factions at a Great Council in November 1457, Sir Geoffrey Boleyn raised a strong force of citizens to ensure that there was no breach of the peace.

[20] In the first year of Edward IV the manor of Abbotsley, Huntingdon ("formerly called Scottesmanner"), was confirmed to him by patent,[21] and in 1461 he and "Geffray Feldyng" headed the list of contributors towards a prest of 500 marks granted to the king by the fellowship of the Mercers for the Earl of Warwick to go into the North.

[24] Of Blickling, Blomefield remarks, "He built the chapel of St Thomas, at the east end of the north aisle of Blickling church, and adorned the windows with beautiful painted glass, and there still remain his own arms impaling his wife's in a window there, and this inscription:'...... Galfrida Boleyn quondam Domini istius Ville, et Anne Consortis sue, qui istam Capellam una cum Fenestra fieri [fecerunt], quorum animabus propicietur Deus.'

By his inquisition post mortem, held in that year, it was shown that in Kent he held the manors of Kemsing, Seal, Hever Cobham and Hever Brocays, and Chiddyngton; in Sussex, Pashley Manor in Ticehurst (as of the Rape of Hastings); in London, various properties in the area of St Mary Aldermary church, Wood Street, Milk Street and Westcheap; and in Norfolk, Blickling, Mulbarton, Horsford, Holkham (as of Buckenham Castle), Stiffkey, Filby, Postwick, Carbrooke and West Lexham.

The church of St Lawrence Jewry was destroyed in the Great Fire of London, but the memorial inscription was recorded by John Weever:"Hic incineratur corpus quondam Gaulfridi Bulleyn, civis, merceri et majoris London, qui ab hac luce migravit 1463, cuius anime pax sit perpetua.