Robert FitzHamon, probably born in the 1040s or 1050s, was the son of Hamo Dapifer the Sheriff of Kent and grandson of Hamon Dentatus ("The Betoothed or Toothy", i.e., probably buck-toothed).

After the revolt was defeated he was granted as a reward by King William Rufus the feudal barony of Gloucester[2] consisting of over two hundred manors in Gloucestershire and other counties.

The chronology of Robert's conquest of Glamorgan is uncertain, but it probably took place in the decades after he received the feudal barony of Gloucester.

As reward Robert took possession of Glamorgan, and "the French came into Dyfed and Ceredigion, which they have still retained, and fortified the castles, and seized upon all the land of the Britons."

Legend has it that Robert had ominous dreams in the days before Rufus' fatal hunting expedition, which postponed but did not prevent the outing.

He was one of the first to gather in tears around Rufus' corpse, and he used his cloak to cover the late king's body on its journey to be buried in Winchester.

By his wife, Robert Fitzhamon is said to have had four daughters including: A depiction of Robert FitzHamon (d. 1107) and Richard I de Grenville (d. post 1142) is contained within one of the two Granville windows by Clayton and Bell[6] erected in 1860 by descendants of the latter within the Granville Chapel of the Church of St James the Great, Kilkhampton, Cornwall.

The Granvilles claimed in the 17th century to have been the heirs male of Robert FitzHamon to a non-existent Earldom of Corboil, a connection without historical foundation.