In 55 B.C. the triumphal general Pompey the Great dedicated Rome's first permanent theatre and named it after himself. This was no ordinary theatre. Pompey's sumptuous and grandiose edifice probably the largest theatre ever built comprised, in addition to the Theatre itself (the stage of which was 300 feet wide), an extensive "leisure-complex" of gardens enclosed within a colonnade, and galleries displaying rare works of art. It also included a curia (a meeting house for the Senate), and it was in this building that Caesar was assassinated in 44 B.C. A grand temple above the uppermost tiers of the auditorium, dedicated to Pompey's patron divinity, Venus Victrix, crowned the entire architecturally unified monument. Although the theatre was built upon the flats of the Campus Martius, this, its highest point, was second in height only to the temple of Jupiter on the capitol. According to our research, the auditorium or cavea beneath it may have accommodated some 25,000 spectators.1 Pompey's gift to the Roman people was for centuries the site of many of the most important events in the cultural and political life of the city.2 Nero himself performed upon its stage,3 much to the disgust of the senatorial class and the delight of the masses. As late as the 6th century A.D., when it was restored for the last time the theatre was still sufficiently imposing for Cassiodorus to exclaim, "one would have thought it more likely for mountains to subside, than this strong building be shaken".4 Over five centuries earlier, when Vitruvius wrote his influential treatise, De Architectura, his detailed account of how a "typical" Roman theatre should be built was based upon Pompey's recently-completed edifice; indeed, at the time he wrote, it was probably still the only stone theatre in the city of Rome.5 Thus, through Vitruvius, the Theatre of Pompey became the architectural Ur-text for many of the numerous theatres built throughout the Roman Empire. Subsequently, in the Renaissance, through the influence of Vitruvius, the Theatre of Pompey left its imprint upon such seminal theatres as the Teatro Olimpico at Vicenza and the Teatro Farnese at Parma. This single theatre, therefore, had a unique