He was a Norman knight who came to England in the Norman Conquest. He held great power in East Anglia, and four of his descendants were Earl of Norfolk.
Roger came from a fairly obscure family of poor knights in Normandy. Robert le Bigot, who was probably Roger's father, acquired an important position in the household of William, duke of Normandy (later William I of England), due, the story goes, to his disclosure to the duke of a plot by the duke's cousin William of Mortain.
Robert or Roger, or perhaps even both, fought at the Battle of Hastings, and afterwards they were rewarded with a substantial estate in East Anglia. The Domesday Book lists Roger as holding 6 lordships in Essex, 117 in Suffolk and 187 in Norfolk.
Bigod's base was in Thetford, Norfolk where he founded a priory later donated to the great monastery at Cluny. In 1101 he further consolidated his power when Henry I granted him licence to build a castle at Framlingham, which became the family seat of power until their downfall in 1307. Two of the places associated with Roger Bigod are Framlingham and Bungay in Suffolk. Framlingham Castle and Bungay Castle were built and improved by successive generations.
In 1069 he, along with Robert Malet and Ralph de Gael (the then Earl of Norfolk), defeated Sweyn I of Denmark near Ipswich. After Ralph de Gael's fall in 1074, Roger was appointed Sheriff of Norfolk and Suffolk, and acquired many of the dispossessed earl's estates. For this reason he is sometimes counted as Earl of Norfolk, but he probably was never actually created earl. He acquired further estates through his influence in local law courts.
In the Rebellion of 1088 he joined other Anglo-Norman barons against William II, who, it was hoped, was to be deposed in favour of Robert Curthose, Duke of Normandy. He seems to have lost his lands after the rebellion had failed, but got them back again.
In 1101 there was another attempt to bring in Robert of Normandy by unseating Henry I, but this time Roger Bigod stayed loyal to Henry.
He died on September 9, 1107 and is buried in Norwich. Upon his death there was a dispute between the Bishop of Norwich, Herbet Losinga and the monks at Thetford, the priory founded by Bigod. The monks claimed that Roger's body, along with those of his family and successors, was due to them as part of the foundation charter of the priory (as was common practice at the time). The issue was apparently resolved when the Bishop of Norwich stole the body in the middle of the night and dragged it back to Norwich.
For some time he was thought to have two wives, Adelaide/Adeliza and Alice de Tosny. It is now believed these were the same woman, Adeliza(Alice) de Tosny(Toeni,Toeny). She was the sister and coheiress of William de Tosny, Lord of Belvoir.
The first of this great family that settled in England, in the Conqueror's time, possessed six lordships in Essex and a hundred and seventeen in Suffolk, besides divers manors in Norfolk. Roger Bigod was one of the tight-knit group of second-rank Norman nobles who did well out of the conquest of England. His territorial fortune was based on his service in the royal household, where he was a close adviser and agent for the first three Norman kings, and the propitius circumstances of post-Conquest politics. This Roger, adhering to the party that took up arms against William Rufus in the 1st year of that monarch's reign, fortified the castle at Norwich andwasted the country around. At the accession of Henry I, being a witness of the king's laws and staunch in his interests, he obtained Framlingham in Suffolk as a gift from the crown. We find further of him that he founded in 1103, the abbey of Thetford, in Norfolk, and that he was buried there at his decease in four years after, leaving, by Adelisa his wife, dau. and co-heir of Hugh De Grentesmesnil, high steward of England, a son and heir, William Bigod, steward of the household of King Henry I. [Sir Bernard Burke, Dormant, Abeyant, Forfeited, and Extinct Peerages, Burke's Peerage, Ltd., London, 1883, p. 53, Bigod, Earls of Norfolk]. Much of his honour in East Anglia was carved out of lands previously belonging to the dispossessed Archbishop Stigand, his brother Aethelmar of Elham, and the disgraced Earl Ralph of Norfolk and Suffolk. Apart from a flirtation with the cause of Robert Curthose in 1088, he remained conspicuously loyal to Rufus and Henry I, for whom he continued to act as steward and to witness charters. The adherence of such men was vital to the Norman kings. Through them central business could be conducted and localities controlled. Small wonder they were well rewarded. Roger established a dynasty which dominated East Anglia from the 1140s, as earls of Norfolk, until 1306. Roger's by name and the subsequent family name was derived from a word (bigot) meaning double-headed instrument such as a pickaxe: a tribute, perhaps to Roger's effectiveness as a royal servant; certainly an apt image of one who worked hard both for his masters and for himself. [Who's Who in Early Medieval England, Christopher Tyerman, Shepheard-Walwyn, Ltd., London,1996]