The following is from the Turner Classic Movies website article about Valley of the Kings.
The author is Jeremy Arnold.  For the full article please visit tcm.com.

“Valley of the Kings was the first major Hollywood production to be filmed in Egypt, and also the first to have its world premiere there. The film shot all over the country, including at an ancient monastery on the Sinai Peninsula. According to a Good Housekeeping article from [1954], the cast and crew traveled 300 difficult miles from Cairo, including a final portion by camel, and lived for a week with the 19 monks who resided there. “They slept on wooden cots in the cells provided for pilgrims and joined the holy men in their meager daily rations. The brothers, members of the Greek Orthodox Church, showed little interest in the filmmaking but were willing hosts and did not object to playing themselves.”

(Photos:  Kurt Kasznar, Robert Taylor, Carlos Thompson; Eleanor Parker, Robert Taylor; Samia Gamal, Robert Taylor.)

“Pirosh later said that he stopped directing movies after 1957 because he couldn’t bear the creative power struggles behind the scenes. On Valley of the Kings, he clashed with MGM production chief Dore Schary and Schary’s underling Charles Schnee. The executives demanded script changes; Pirosh made one or two and ignored the rest. Then, once shooting began in Egypt and rushes were screened back in Hollywood, Pirosh started receiving phone calls demanding to know where the other changes were. “It was real, real tough,” Pirosh later recalled. “One day Charlie Schnee showed up in Egypt. He said, ‘I have instructions from Dore that you either make the changes that I want made or he’s sending over another director.’ So I made the changes. They were not too hard to make, but they changed the character relationships in a way that I didn’t like, and there was a certain amount of friction with the actors.

(Photos: Robert Pirrosh, Parker, Taylor; Parker and Taylor)

“‘I was not good at handling the Robert Taylors in the business,’ Pirosh continued. ‘If the actor is more powerful with the studio than the director, it’s serious trouble for the director. Then the director has to make tremendous compromises and go through all sorts of agony and develops ulcers. I knew that sooner or later I was going to drop out of directing.'”

There was behind-the-scenes drama involving the actors as well. Robert Taylor and Eleanor Parker had previously teamed for Above and Beyond (1952) and had had an affair on that film…. By the time [they] reunited in Egypt on Valley of the Kings, Taylor was involved with young actress Ursula Thiess, and Parker was newly divorced. The two resumed their dalliance. Thiess heard about it, grew jealous, and started seeing other men, making sure the news hit the gossip columns. When Taylor returned home, Thiess refused to see him, which had the intended effect of making him even more jealous. Finally he….. proposed. Thiess accepted, and on May 24, 1954, a few months before Valley of the Kings opened in theaters, they were married.”

(Photos; filming at the Sphinx; Parker, Taylor,  Pirrosh(?))

To add to the difficulties, Robert Taylor was injured early in the filming.  He had to jump off a camel over and over and damaged a knee that had been previously hurt during a hunting trip to Canada.  As he put it, “‘last Sunday morning I got up scarcely able to walk.  I got to work, but when we finished for the day, I got a Doc from the Anglo-American hospital here who examined me, insisted on X-Rays, and pronounced my condition  as something which sounds more than an Italian Liqueur than a bone condition…..Pelligrini-Steida’s [sic] Disease.” This was a calcium deposit on the outside edge of a bone in Bob’s knee joint.  Tendons and nerves rubbing on that joint caused the pain.”  (Linda J. Alexander, Reluctant Witness, North Carolina, Tease Publishing, 2008, p. 285).

(Photos: Taylor tries a mode of transportation safer than a camel.)