Bondage depicted within films details

I’m attempting to recall the names of two films from back in the ’60s, which belong to the sword-and-sandal category. In one film, a woman is brought into a blacksmith’s workshop and pinned down as a steel collar gets fastened around her neck. She might have had other restraints too. I initially thought it was Theodora Slave Empress, but screenshots from that movie don’t quite match up. The second feature shows a group of women linked together by their necks. One woman falls ill (or something similar) and ends up beheaded. When the group arrives at an oasis, there is one empty collar left over. Someone has captured a princess who gets placed into that spare collar, and they head out into the desert.