It was originally claimed that the Exchequer was based on a similar Norman court; however, while there are many records of the Exchequer's work in England, there is no evidence of a similar body in pre-conquest Normandy. The first reliable records come from the time of Henry I, when the sole surviving Pipe roll from his reign shows the Exchequer working out of the king's palace as part of the "curia regis". The "curia regis" followed the king as he travelled rather than sitting at any one fixed location, and was held in York, London and Northampton at various times. By the late 12th century it had taken to sitting in a fixed location (the one body of government in England to do so), and by the 1170s it was possible to distinguish the Exchequer's work from that of the other parts of the "curia regis", although the king of the time considered the Exchequer to simply be an element of the "curia"; indeed, it was referred to as the "Curia Regis ad Scaccarium", or King's Court at Exchequer. The word "Exchequer" derives from the chequered cloth laid on a table for the purposes of counting money. In the 1190s the Exchequer began separating from the "curia regis", a process which continued until the beginning of the 13th century; academics have suggested that this is due to an increasing demand on the revenue side of the court, which led to part of the common law element being split off to form the Court of Common Pleas. Although the Exchequer of Pleas was the first common law court, it was also the last to separate from the "curia regis".