Sir Gilbert Fitz Gilbert de Clare, 1st Earl of Pembroke, b. ca.1100, Tonbridge, Kent, England, d.1148, England.
Sometimes refered to as "Strongbow" but his son is better remembered by this name. Became a great baron, obtaining the estates of his paternal uncles, Roger and Walter, which included the baronies and castles of Bienfaite and Orbec in Normandy, the lordship of Nether Gwent and the castle of Striguil (later Chepstow). King Stephen created him Earl of Pembroke, and gave him the rape and castle of Pevensey. At Stephen's defeat at Lincoln 2 Feb 1140, he was among those who rallied to Empress Maud when she recovered London in June, but was at Canterbury when Stephen was recrowned late in 1141. He then joined Geoffrey's plot against Stephen, but when that conspiracy collapsed, he was again adhered to Stephen, being with him at the siege of Oxford late in 1142. In 1147 he rebelled when Stephen refused to give him the castles surrendered by his nephew Gilbert, 2nd Earl of Hertford, whereupon the King marched to his nearest castle and nearly captured him. However, the Earl appears to have made his peace with Stephen before his death the following year.
Spouse:

• m. Isabel de Beaumont, (1112-1172), daughter of Sir Robert de Beaumont, Earl of Leicester, Count of Meulan, and Isabel de Vermandois, before 1130. She had previously been the mistress of King Henry I of England
  

Children:

• Agnes de Clare, b. ca.1112, Tonbridge, Kent, England.
• Baldwin de Clare, b. ca.1114, Tonbridge, Kent, England.
• Basilia de Clare, b ca.[[1116], Tonbridge, Kent, England.
• Sir Richard Fitz Gilbert de Clare [n] "Strongbow", 2nd Earl of Pembroke,(1130-1176).

Parents:

• Sir Gilbert Fitz Richard, Lord of Clare, Tonbridge, and Cardigan, (1066-1115).
• Adelize/Alice de Claremont, b. ca.1058, daughter of Hugh de Creil, Count of Clermont, and Margaret de Roucy.