|Bishop of Carlisle|
|Elected||22 August 1223|
|Predecessor||Hugh of Beaulieu|
|Successor||Silvester de Everdon|
|Other post(s)||Canon of Carlisle Cathedral|
|Died||c. 28 October 1248|
13 November 1228 – 1233
|Preceded by||Eustace of Fauconberg|
|Succeeded by||Peter des Rivaux|
Mauclerk's origins are unknown, although he had a brother who was prior of Reading Abbey. Another kinsman, possibly a nephew, Robert Barri was named prior of Carlisle Cathedral while Walter was bishop. He is first recorded as a financial clerk in Normandy in 1202, and then later that same year as holding a church in Falaise. With the loss of Normandy, he returned to England and the king's court, and received a prebend in Exeter in 1203. In 1204 and 1205 he helped administer Lincolnshire, collecting tallage other taxes. He served King John of England in Rome as an envoy to Pope Innocent III in 1214 where he was expected to neutralise any baronial agents that might be sent. At the time, he was still a royal clerk. In 1215, he was sent to Ireland, although only for a short time. He served as a royal justice in the Midlands in 1218, and as a royal justice in Nottingham in 1219, and in 1221 appointed as a forest justice in York, but was instead sent to Cumberland. He served as Sheriff of Cumberland from 1222 to 1233. He was a canon of Carlisle Cathedral before he was elected to the see of Carlisle about 22 August 1223 and was consecrated that winter.
Mauclerk continued to serve King Henry III of England, going to Cologne in 1225 as part of a diplomatic mission attempting to arrange a marriage between the king and a daughter of the duke of Austria. In 1227 he was in Poitou on the king's business. He was Treasurer from 1228 to 1233, when he was expelled from office even though he had been granted the office for life. This was a side effect of the fall from power of Hubert de Burgh during King Henry III's reign. However, with the fall from power of Peter des Roches Walter returned to royal service. In 1235 he was once more in charge of an embassy attempting to find a bride for King Henry, this time to Flanders for a daughter of the count of Ponthieu.
Mauclerk resigned the see on 26 June 1246 and died about 28 October 1248 at Oxford. He resigned the bishopric to become a Dominican at Oxford. During his time as bishop, he set the financial affairs of his diocese on a firm footing, and left most of his property to the diocese or to the Dominicans at Oxford.
- Vincent "Mauclerk, Walter" Oxford Dictionary of National Biography
- Pegues "Clericus in Legal Administration" English Historical Review pp. 534–535
- Jones King John and Magna Carta p. 50
- Carpenter "Decline of the Curial Sheriff" English Historical Review p. 11
- Greenway Fasti Ecclesiae Anglicanae 1066–1300: Volume 2: Monastic Cathedrals (Northern and Southern Provinces): Carlisle: Bishops
- Fryde, et al. Handbook of British Chronology p. 235
- Fryde, et al. Handbook of British Chronology p. 103
- Powell and Wallis House of Lords p. 154
- Carpenter, D. A. (January 1976). "The Decline of the Curial Sheriff in England 1194–1258". The English Historical Review. 91 (358): 1–32. doi:10.1093/ehr/XCI.CCCLVIII.1. JSTOR 565189.
- Fryde, E. B.; Greenway, D. E.; Porter, S.; Roy, I. (1996). Handbook of British Chronology (Third revised ed.). Cambridge, UK: Cambridge University Press. ISBN 0-521-56350-X.
- Greenway, Diana E. (1977). "Carlisle: Bishops". Fasti Ecclesiae Anglicanae 1066–1300. Vol. 2: Monastic Cathedrals (Northern and Southern Provinces). Institute of Historical Research. Retrieved 20 October 2007.
- Jones, J. A. P. (1971). King John and Magna Carta. London: Longman. ISBN 0-582-31463-1.
- Pegues, Frank (October 1956). "The Clericus in the Legal Administration of Thirteenth-Century England". The English Historical Review. 71 (281): 529–559. doi:10.1093/ehr/LXXI.281.529. JSTOR 556837.
- Powell, J. Enoch; Wallis, Keith (1968). The House of Lords in the Middle Ages: A History of the English House of Lords to 1540. London: Weidenfeld and Nicolson. OCLC 463626.
- Vincent, Nicholas (2004). "Mauclerk, Walter". Oxford Dictionary of National Biography (online ed.). Oxford University Press. doi:10.1093/ref:odnb/18355. (Subscription or UK public library membership required.)