Dream of the Red Chamber is a masterpiece of Chinese vernacular literature and one of China's Four Great Classical Novels. The novel was composed some time in the middle of the 18th century during the Qing Dynasty and attributed to Cao Xueqin. Redology is the field of study devoted exclusively to this work and the novel is generally acknowledged as the pinnacle of the classical Chinese novels. The novel is believed to be semi-autobiographical, mirroring the fortunes of Cao's own family. As the author details in the first chapter, it is intended to be a memorial to the women he knew in his youth: friends, relatives and servants. The novel is remarkable not only for its huge cast of characters (most of them female) and psychological scope, but also for its precise and detailed observation of the life and social structures typical of 18th-century Chinese aristocracy. This novel was published anonymously but 20th-century Redologists have ascertained its author to be Cao Xueqin, based on circulated commentaries penned in red ink on many of the early handcopied versions known as the "Rouge Versions"