Huizinga had an aesthetic approach to history, where art and spectacle played an important part. His most famous work is The Autumn of the Middle Ages (a.k.a. The Waning of the Middle Ages) (1919). Worthy of mentioning are also Erasmus (1924) and Homo Ludens (1938). In the latter book he discussed the possibility that play is the primary formative element in human culture. Huizinga also published books on American history and Dutch history in the 17th century. Source.