The seven conspirators, usually called "Pharaohs" in Tibia, are powerful creatures. At one time, they were trusted advisors to the Pharaoh Arkhotep, who was their former leader and fellow conspirator.
Because of their conspiracy against Arkhotep, they were banished to seven different tombs beneath the sand, eternally undying.
With the help of Morgathla, it was Arkhotep that began forging the high mask of the ancients again, after the secrets of the mask were thought to be long forgotten. He taught each of his advisors the secret to forge a single part of the mask, knowing that they would never share their knowledge with eachother.
The 8th pharaoh, Ashmunrah was appointed to guard the sacred altar used to fuse the helmet pieces together.
An interesting piece of trivia is that although these creatures are referred to as Pharaohs, they are infact undead conspirators with no royal title or blood claim.