published his influential work The Renaissance of the Twelfth Century in 1927. Three medieval renaissances were thus established, corresponding to the 8th, 10th, and 12th centuries.

The terms Carolingian Renaissance, Ottonian Renaissance, and 12th-century Renaissance must be distinguished from the work of historians such as Jacob Burckhardt, who sought medieval roots for the 16th-century Renaissance. The concept of medieval renaissances draws on the latter but applies the idea of cultural renewal