George Pan Cosmatos was a Greek-Italian film director and screenwriter. Following early success in his home country with drama films such as Massacre in Rome with Richard Burton, Cosmatos retooled his career towards mainstream "blockbuster" action and adventure films, including The Cassandra Crossing and Escape to Athena, both of which were British-Italian co-productions. After relocating to North America, he directed the horror film Of Unknown Origin. This was followed by some of his best-known work, including the action films Rambo: First Blood Part II and Cobra, the science-fiction horror film Leviathan, and the critically acclaimed Western Tombstone.

Massacre in Rome is a 1973 Italian war drama film directed by George Pan Cosmatos about the Ardeatine massacre which occurred at the Ardeatine caves in Rome, 24 March 1944, committed by the Germans as a reprisal for a partisan attack against the SS Police Regiment Bozen. The film was based on the 1967 book Death in Rome by Robert Katz. An Italian court gave producer Carlo Ponti and director Cosmatos a six-month suspended sentence for their film which claimed Pope Pius XII knew of and did nothing about the execution of Italian hostages by the Germans. The charges eventually were dropped on appeal. The names of the victims are shown in the closing credits, as opposed to the cast credits and crew members.