The Complete Credits of Caligula
This is a set of 16 Lobby Cards from a Theatre in Germany. Many of these cards were distributed to theatres all over the world. his set is from 1981. I own a fair amount of lobby cards, and I plan to get them up soon, there is probably 3-4 different sets, mostly with all the same pictures.
This is a set of 8 Lobby Cards for the 1985 German  re-issue of Caligula with some new footage. (Pix April 23/01)
It is thought that at least 2,500 people contributed to the movie, between the film crew, extras, caterers, and the main actors. Here is a known list so far:
Directed by: Tinto Brass, Bob Guccione & Giancarlo Lui
Original Script by:
Gore Vidal, adapted for film by Massolino D'Amico, who was
    also the translator for the film.
Script based on a treatment by Roberto Rossellini

The Cast:
Malcolm McDowell-Caligula
Teresa Ann Savoy-Drusilla
Helen Mirren-Caesonia
Peter O'Toole-Tiberius
John Steiner-Longinus
Guido Mannari-Macro
Patrick Allen-Macro (Uncredited Voice)
Paolo Bonacelli-Chaerea
Leopoldo Trieste-Charicles
Giancarlo Badessi-Claudius
Mirella D'Angelo-Livia
Anneka Di Lorenzo-Messalina
Lori Wagner-Agrippina
Adriana Asti-Ennia
Sir John Gielgud-Nerva
Bruno Brive-Gemellus
Richard Parets-Mnester (Directs the street play)
Paula Mitchell-Subura Singer (In the street play scene)
Osiride Pevarello-Mute Giant (Historically known as Sabinus)
Donato Placido-Proculus
Eduardo Bergara Leumann-High Priest of Rome
Lucky Fellows-Imperial Bordello Extra
Roman Extra-Bacchus, The Roman God of Wine
Roman Extra-Jail Whore
Roman Extra-Tiberius' Nubian Crutch (Taste Tester from Grotto Scene)
Roman Extra-Drunken Sentry at Tiberius' Grotto
Roman Extra-Officer of the Guard at Tiberius' Grotto
Roman Extra-Grotto Nymph from Britian
Roman Extra-Tiberius' Nubian Grotto Stallion
Roman Extra-Grotto Hermaphrodite
Giuseppe "Pino" Ammendola-Uncredited
Gerardo Amato-Uncredited
Eolo Capritti-Caligula's Executioner (Man who kills Proculus)
Roman Extra-Tragedy (Dwarf)
Roman Extra-Comedy (Dwarf)
John Francis Lane-Guest at Livia & Proculus' Wedding
Giuseppe Maffioli I-Master of Ceremonies (Wedding Scene & Celebration Feast)
Caramella-Male in the Secret Room
Belladonna-Male in the Secret Room
Juliet Morris-Imperial Bordello Worker
Jane Hargrave -Priestess in the Temple of Isis
Helen Lang-Priestess in the Temple of Isis
Signe Berger-Imperial Bordello Worker
Susanne Saxon-Imperial Bordello Worker
Henrietta Kelogg-Imperial Bordello Worker
Bonnie Dee Wilson-Imperial Bordello Worker
Melanie Sutherland-Imperial Bordello Worker
Carolyn Patsis-Diana
Valerie Rae Clark -Senator's Wife/Priestess of Isis/Imperial Bordello Worker

Produced By-Bob Guccione,
Franco Rossellini
Excutive Producer-Jack H. Silverman
Original Music-Toni Biggs (We Are One)
Original Music-Paul Clemente
Non-Original Music-
Aram Khachaturyan & Sergei Prokofiev
Cinematography-Tinto Brass, Bob Guccione, Silvano Ippoliti & Giancarlo Lui
Boom Operator-Giuliano Maielli
Camera Operator-Pino Di Biase
Camera Operator-Enrico Sasso
Film Editing-Nino Baragli & H. Russell Lloyd
Asst. Editor-Stuart Urban & Peter Krook
2nd Assistant Editor-
Luca Ronchi
Art Direction, Costume Design & Production Designer-
Danilo Donati
Make Up-Giuseppe Banchelli (Artist) & Jole Cecchini (Hair Stylist)
Production Management-Mario Di Biase
Production Supervisors-Augusto Marabelli & Alessandro Mattei
First Assistant Director-
Piernico Solinas
Set Dresser-Luigi Urbani
Property Master-Gianpiero Grassy
Sound Dubbing Mixer-Gerry Humphreys
Sound Mixer (Italy)-Stefano Morandi
Dialogue Editor-Archie Ludski
Sound Engineer-Claudio Maielli
Sound Mixer-Robin O'Donoghue
Sound Editor-Winston Ryder (Supervisor) & Roger VanEngel
Special Effects-Franco Celli & Marcello Coccia
Script Continuity-Carla Cipriani
Unit manager-Sergio Galiano
Choreographer-Tito LeDuc & Pino Pennesi
Casting By-Carlo Heusch & Roberto Tatti
Wardrobe Mistress-Gloria Picone Musetta
Wardrobe Master-Gregorio Simili
Architect-Giovanni Natalucci & Franco Velchi
Researcher-Pola Kurlancheek
Consultant on Gastronomy-Giuseppe Maffioli II
Dialogue Director-Louise Vincent
Unit Photographer (Stills)-Mario Tursi
Special Photographers (Auditions & Promotions)-Eddie Adams, Jerry Bauer,
            Stan Malinowski and Claudio Patriarca
Unit Publicist-Walter Alford and Maria Ruhle
Asst. to the Producers-Leslie Jay
Technical Equippment-Cinenoleggion
Costume Rental-Ferani Veste
Shoes-L.C.P. di Pompei
Props-Rancate of Sormani
Medical Intern-
Aleta Karadej
Accountants-SOC G.E.S.C.A. SPA
Helen was not actually in the film