 _Mummy, The (1932)_ (qv) was set in 1932, the year of its release.  The first sequel, _Mummys Hand, The (1940)_ (qv) is also  chronologically coherent, set in 1940.  _Mummys Tomb, The (1942)_ (qv) takes place thirty years following  the events of "Hand", with _Mummys Ghost, The (1944)_ (qv)  approximately two years after that. We learn that this movie is set  an additional twenty five years after "Ghost", meaning that the  events take place around 1997.