Eberhard of Béthune was a Flemish grammarian of the early thirteenth century, from Arras

Arras

Arras is the capital of the Pas-de-Calais department in northern France. The historic centre of the Artois region, its local speech is characterized as a Picard dialect...

. He was the author of Graecismus, a popular Latin grammatical poem

Latin mnemonics

A Latin mnemonic verse or mnemonic rhyme is a mnemonic device for teaching and remembering Latin grammar. Such mnemonics have been considered by teachers to be an effective technique for schoolchildren to learn the complex rules of Latin accidence and syntax...

, dated to c. 1212. The name came from a short section on the Greek language

Greek language

Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

. His Laborintus is an elaborate and critical treatise on poetry and pedagogics; it is also known as De Miseriis Rectorum Scholarum.

He was also actively engaged against the Waldensians

Waldensians

Waldensians, Waldenses or Vaudois are names for a Christian movement of the later Middle Ages, descendants of which still exist in various regions, primarily in North-Western Italy. There is considerable uncertainty about the earlier history of the Waldenses because of a lack of extant source...

, and wrote a book Antihaeresis against them. He is cited in Foxe's Book of Martyrs

Foxe's Book of Martyrs

The Book of Martyrs, by John Foxe, more accurately Acts and Monuments, is an account from a Protestant point of view of Christian church history and martyrology...

as to the etymology of the name.