George Pan Cosmatos (4 January 1941 – 19 April 2005) 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 (based on the real-life Ardeatine massacre), 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 "" and "Cobra" (both of which star Sylvester Stallone), the science-fiction horror film "Leviathan", and the critically acclaimed Western "Tombstone".