John of Salisbury was born in southern England, journeying thence to Paris and Chartres in 1136 in order to study with, among other great teachers of his day, Abelard and (later) the rhetorician Thierry of Chartres. After ordination to the priesthood, he returned to England in 1154, having been appointed secretary to the then-Archbishop of Canterbury, Theobald. During the following years he composed his Policraticus, a treatise on political theory, as well as his Metalogicon, a defense of the study of the liberal arts and one of the central texts in the history of medieval pedagogy. (Two collections of the letters of John of Salisbury also survive, and as a Latin letter-writer in the twelfth century, as a practitioner of the ars dictaminis, John is unparalleled.) Both of John's major works were upon completion sent in 1159 to Thomas Becket, then chancellor to Henry II; when Becket became archbishop himself in 1161, John continued to serve as his secretary, becoming his close friend. He was exiled along with Becket by Henry II, and saw the murder of his friend in 1170. John himself died on October 25, 1180.