In the levity of his tongue and the foolishness of his heart

From English history, from 1235 to 1273 by Matthew Paris. Summary - an Englishman in the 1250s or so gets in trouble in England and is banished. He flees to the Middle East where he loses all his money gambling. Being able to write and fluent in several languages, the Tatars make him a proposition he cannot refuse. A happy-go-lucky English ne'er-do-well who ends up in service to the Tatar as a translator and emissary.

An amazing tale, fortuitously related by Paris.

The prince of Dalmatia took prisoners eight of the fugitives, one of whom was known by the duke of Austria to be an Englishman, who, for certain crimes, had been banished for ever from the kingdom of England. This man had twice come as an envoy and interpreter from the king of the Tattars to the king of Hungary, and plainly threatened and warned them of the evils which afterwards happened, unless he should give up himself and his kingdom to be subject to the Tattars. The princes persuaded him to speak the truth about the Tattars, and he, without hesitation, under every form of oath, made his statements so strongly that the devil himself might have been believed. First, he told about himself, that immediately after his banishment, that is, before he was thirty years old, he lost all he had at gambling, in the city of Acre; and in the winter-time had nothing but a shirt of sackcloth, shoes of ox's skin, and a cape made of horsehair. In this shameful state of want, and in an enfeebled state of body, with his hair cropped as if he were a buffoon, and uttering inarticulate cries like a dumb man, he passed over many countries, and met with great kindness from his entertainers, wearing out his life somehow or other, though he daily, in the levity of his tongue and the foolishness of his heart, had wished himself at the devil. At length, from excessive toil, and continual change of air and diet, he was seized with a severe illness, among the Chaldees, and became weary of his life. Not able to go farther, or to come back, he stopped where he was, breathing with difficulty, and, being somewhat acquainted with letters, he began to put down in writing the words which were there spoken, and afterwards pronounced them so correctly that he was taken for a native, and he learnt several languages with the same facility. The Tattars heard of him through their spies, and drew him over to their interests: when they had got an answer about their claim of subjugating the whole world, they bound him to be loyal in their service, by bestowing on him many gifts; for they were in much need of persons to be their interpreters.