From the early days of printing the church had tried to censor books, drawing up an index of forbidden ones.

ECONOMIST: Millennium issue: COMMUNICATION

When I was doing doctoral research in the late 1980s, the University of Jordan housed a massive collection of books in what was then called the "forbidden room" of the school's library.

NPR: Historian Robert Satloff

Fourteen Ming and 10 Qing emperors called the Forbidden City home and the intrigue, scandal and drama that went on here has inspired countless films and books.

BBC: Beijing's once Forbidden City