A manuscript which narrates the descents of the founders of Lanthony Abbey names “dominus Humfridus quartus de Bohun, comes Herefordiæ et constabularius Angliæ” as son of “dominum Hunfredum de Bohun tertium” and his wife “Margeriam”.
He succeeded his father as Lord of Trowbridge, Wiltshire. The 1164/65 Pipe Roll records "Hunfr de Bohu" owing ".ccc. m p Releuio terre patris sui" in Wiltshire, which implies that Humphrey senior had recently died. The Red Book of the Exchequer records enfeoffments in the duchy of Normandy in , "Humfridus de Boun" with two knights and two knights "in Costentino" in his own service.
He was appointed Constable of England by , presumably inheriting the position from his mother's family.
Robert of Torigny records the death in 1182 of "Hunfredus de Bohun". A manuscript which narrates the descents of the founders of Lanthony Abbey records that “dominus Humfridus quartus de Bohun, comes Herefordiæ et constabularius Angliæ” was buried at Lanthony. A manuscript in Aske’s collections names “Milo…Erle of Herforde, Lord of Bricone and of all the Forest of Done, and also Constable of England…Ladi Margaret the furst begotton daughter of the said Milo…married to Humfre of Bohun the third…Humfre of Bohum the iiiith sonne and heire of the foresaid Margaret…” among those buried at Lanthony Priory. 1
Humphrey de Bohun was Earl of Hereford and Constable of England in right of his mother, if the Chronicles of Llanthony be correct. His lordship m. Margaret of Scotland, dau. of Henry, Earl of Huntingdon, sister of William, King of Scots, and widow of Conan le Petit, Earl of Brittany and Richmond, and was s. by his son, Henry de Bohun, 1st Earl of Hereford. 2