- Born: Abt 1125, , , England
- Marriage: Henry I D'ESSEX, Lord Of Rayleigh, Constable 
- Died: , , England
[Agnes's mother = Alice de Montfort or Cecily ?]
"2. HENRY de Essex . ... m CECILY, daughter of ---. "Henry de Essex, the king´s constable" confirmed his parents´ donation of Fremingham church to Thetford priory, Norfolk for the souls of "Cecily his wife, Henry his son and his other children". "Henricus de Essexia" confirmed the donation of "ecclesiam de Walde" to Clerkenwell St Mary´s made by "Cecilia mater mea", by undated charter. Henry & his wife had [four or more] children:
a) HENRY de Essex (-after 1210).
b) HUGH de Essex (-after Mar 1194).
c) AGNES de Essex ([1151/52]-after 1206, bur Colne Priory). ...
d) other children. ..."
"Henry of Essex or Henry d'Essex (died c. 1170) was a Norman noble who held the honours of Rayleigh, Essex, ...
He married first a woman named Cecily, by whom he seems to have had two sons, Henry and Hugh. His second marriage to Alice de Montfort, widow of Robert fitz Bernard de Vere, produced at least one daughter, Agnes of Essex. Agnes was betrothed in childhood to Geoffrey de Vere, brother of the first earl of Oxford, but later married Aubrey de Vere III, first earl of Oxford, as his third wife."
N. married Henry I D'ESSEX, Lord Of Rayleigh, Constable  [MRIN: 2302], son of Robert D'ESSEX, Lord Of Rayleigh  and Gunnor BIGOD . (Henry I D'ESSEX, Lord Of Rayleigh, Constable  was born about 1125 in , , England, died in 1170 in , , England and was buried in Reading Abbey, Berkshire, England.)