Hans Chiari (1851–1916) (Fig. 1) gave the first detailed illustrations of what is now termed the Chiari malformations. In 1891, he described several congenital anomalies affecting the cerebellum due to hydrocephalus, and this paper listed three different types of abnormalities [1]. Four years later, in 1895, Chiari wrote a second paper (Fig. 2) that described the type IV malformation in two patients [2].