The Reinheitsgebot (German pronunciation: [ˈʁaɪnhaɪtsɡəˌboːt] ; lit. 'purity order') is a series of regulations limiting the ingredients in beer in Germany and the states of the former Holy Roman Empire. The best known version of the law was adopted in Bavaria in 1516 (by William IV), but similar regulations predate the Bavarian order, and modern regulations also significantly differ from the 1516 Bavarian version. Although today the Reinheitsgebot is mentioned in various texts about the history of beer, historically it was only applied in the duchy, electorate, then Kingdom of Bavaria and from 1906 in Germany as a whole, and it had little or no effect in other countries or regions.