Caligula Shooting Schedule
June 1975-The film begins, locations are scouted, scripts are finalized, casting
     begins, and sets are begun to be built, 64 in all. As well, 3,592 costumes
     have to be made, not including 2,000 pairs of sandals.
Spring 1976-The huge outdoor set is begun just outside of Rome, and not
     too far away from Dear Studios. This outdoor set houses the Capri        
     exteriors,  nd after they are shot, the set is converted to the Stadium.
June 7 1976-Piernico "Nico" Solinas , the Assistant Director, puts the word out
     that he will need up to 15,000 extras for the movie.
June/July 1976-Nico Solinas holds "sex tests" for the extras, to make sure they
     will do ANYTHING for the camera. He films about 150 girls having sex of
     every sort!
June 18 1976-Gore Vidal quits the production when Tinto and Malcolm work
     on the script.
June 26th 1976-Rewrites on the script
July 1976-Casting for the main roles is finished.
August 5 1976-Filming begins! The Capri sequences are shot; The
      Phallic Slope, Torture Ward, Harum of the Monsters, Tiberius' Pool,
      and Nerva's bed Chamber.
Sept 7 1976-Maria Schneider walks off the set during sex scenes with Malcolm
     McDowell. She tells the press that Caligula was "a grotesque pornographic
     movie". Teresa Ann Savoy is cast for Drusilla.
September 1976-The Capri Set is dismantled, and replaced with the
     Stadium set, shooting is to begin in December.
September 1976-Anneka, Lori and Jane arrive in Rome.
                       -Threesome scene shot with Malcolm, Helen & Teresa. This
                           is the scene that Helen said "got out of hand".
                       -Little Boots dance in the rain scene shot.
                       -The torture & castration of Proculus scene is shot
                       -Bedroom scenes with Teresa and Malcolm shot.
October 1976-5 More pets arrive in Rome, but 3 leave as soon as they find out
                           that they are to be featured in a hard core flick, and not the
                           new James Bond movie!
                    -Battle of Britian Celebration scene shot, a orgy scene is shot
                        but not used.
                    -Battle of Britian scene shot.
                    -Death of Gemellus scene shot
                    -Caesonia's dance scene shot.
November 1976-The Marriage of Proculus & Livia scenes shot.
                       -Several more Pets arrive in Rome
                       -Temple of Isis scenes shot with Pets & Italian actresses.
                       -Death of Drusilla scene shot.
                       -Treasury scene shot. (Not used)
                       -Temple of Jupiter scene shot. (Not used in film)
                       -Suburra & Prison scenes shot on location at the "Baths of
                          Caracalla" near Rome.
December 1976-Imperial Bordello Scene shot (Tinto's version)
                       -Proculus escapes the killing machine scene shot. (Not used
                            in final cut.)
                       -All Stadium scenes shot-Caligula's death, Macro's death, etc.
Dec 24 1976-Last scenes shot with Tinto, he returns to Twickenham
                      Studios in London with the negative, 120 miles worth!
January 1977-Bob Guccione returns to the set with a small crew and
               some Pets, and re-shoots the Imperial Bordello scene, the
               lesbian scene with Lori and Anneka, and other incidental
scenes to be edited in where-ever the hell they thought would be     
               good! Some Pets were ONLY used for these hard-core scenes.
April 19 1977-Tinto Brass fired as director.
July 7 1977-Tinto wins the right in court to edit the movie, but Bob and Franco
                    don't give him the chance.
August 1977-Penthouse sues Tinto, counter sues Gore Vidal.
May 1979-Caligula shown at Cannes in a 3 1/2 hour form. Lawsuits still
July 1979-Court cases with Gore Vidal and Tinto Brass are settled.
Nov 1979-Caligula shown in Italy
Feb 1980-Caligula opens in the USA, New York City!

A very cool press kit I found on E-Bay. It is from about 1979-1980.