Chevalier O'Gorman
IRISH ARMY OFFICER IN THE FRENCH SERVICE AND ANTIQUARIAN
Chevalier Thomas O’Gorman
Tomás, Chevalier O'Gorman or Tomás Ó Gormáin (or Mac Gormáin)Mac Gormáin is the correct version: see Mac Lysaght, Edward, The Surnames of Ireland, Irish Academic Press, 1980 (5th edition), p. 132.