After King Henry's death, Barre became a royal justice during Richard's reign and was one of the main judges in the period from 1194 to 1199.

[1] Another fellow student wrote a short verse addressed to Barre: "Pontificum causas regumque negocia tractes, Qui tibi divicias deliciasque parant", which translates to "May you manage the causes of bishops and the affairs of kings, Who provide riches and delights for you.

With the failure of the negotiations, Becket restored the sentences of excommunication on a number of royal officials, but Barre was not included among those specifically named even though many of his colleagues were.

[10] The mission's objective was to make it clear to Alexander that Henry had had nothing to do with Becket's murder and that the king was horrified that it had taken place.

[2] Although the mission was not a complete success, the royal commission did manage to persuade the papacy not to impose an interdict, or ban on clerical rites, on England or to excommunicate the king.

[17] In February or March 1198, King Henry sent Barre on a diplomatic mission to the continent with letters to Frederick Barbarossa, the German Emperor; Béla II, the King of Hungary; and Isaac II Angelos, the Emperor at Constantinople,[18] seeking assistance for his projected crusade.

[20] After the death of King Henry, Barre joined the service of William Longchamp, the Bishop of Ely, who was justiciar and Lord Chancellor.

[22] Longchamp's exile meant that Barre did not serve as a royal justice again until King Richard I returned to England in 1194.

His last sure mention in the historical record is on 9 August 1202,[27] when he was serving as a judge-delegate for Pope Innocent III,[16] but he may have been alive as late as 1213, as he was part of a papal panel deciding a case that can only be securely dated to between 1198 and 1213.

[28] Barre wrote a work on the Bible entitled Compendium de veteri et novo testamento, which he dedicated to Longchamp.

Richard Sharpe, a modern historian who studied both works, stated that the Harley manuscript "provides [a] well structured and systematic (though not complete) coverage of the whole Bible."

The same catalogue also records five books once owned by Barre—copies of Gratian's Decretum, Justinian's Codex, glossed copies of the Psalter and some of the Epistles of Paul, as well as Peter Lombard's Sentences.