"Never raised his voice, never lost his temper," the actor who plays Gimli the dwarf in the trilogy told reporters in New York.
"Couldn't have gotten more than three or four hours of sleep for the entire shoot. Now directors live on adrenalin, but not for 14 months of principal photography," he observed.
Rhys-Davies admitted he approached the project as a "complete skeptic," noting no single filmmaker had ever tried to make three huge epics simultaneously before.
"I didn't really think it would be successful, to be honest with you," he confessed. "I thought: 'Peter Jackson? Good director, small films. What is there to suggest that he can produce a masterpiece.'"
Rhys-Davies said he felt better the moment he checked out the film set.
"I watched the man direct and the way he handled his crew and I talked to him about his vision," he recalled. "I'm proud to say that I was the first person who actually turned around at the end of two weeks and said: 'Guys? We are making a masterpiece. Make no mistake about it. This is going to be one of the great films of all time.'"
2014: The Year in Music [PHOTOS]