Orson Welles

Justinian

Laurence Harvey

Cethegus

Sylva Koscina

Theodora

Harriet Andersson

Mathawsintha

Michael Dunn

Narses

Ingrid Boulting

Julia (as Ingrid Brett)

Dieter Eppler

Thorsmund

Lang Jeffries

Belisar

Robert Hoffmann

Totila

Ewa Strömberg

Rauthgundis

Mircea Anghelescu

Aligern

Ion Dichiseanu

Furius

Adela Mărculescu

Aspa

Adrian Mihai

Emanoil Petruţ

Teja

Florin Piersic

Witichis

Friedrich von Ledebur

Hildebrand

Fory Etterle

Joachim Nottke

Narrator (uncredited)