» Thu Nov 26, 2009 2:56 pm
There's a main consensus about the Amulet of Kings being of Ayleid origin, and Mankar Camoran being of Ayleid desceent --- therefore he can wear it (That was a terrible summary, but those who don't know what I'm talking about can read in the threads that Adanorcil linked)
I however think that it is related to the bloodlines (and if you look at it that way, genetics).
I think Mankar is part of another line of the Dragonborn. This is not like the Biblical line of Leviticus (sorry to get religious here), where the firstborn sons where the only ones allowed to be priests in the temple. (And please don't debate about that, it's just a small reference)
(http://www.uesp.net/wiki/Tamriel:Third_Era)Emperor Antiochus had many wives and mistresses, which no doubt led to many legit and bastard children. There are also many other Empresses and Emperors that weren't very close to the Septim line(Katariah the wife of Mad Pelagius, Uriel IV, etc, to name a few). So all that is need to rule (and to wear the Amulet of Kings), is the blood of the Septims. This is backed up (mostly, but he also quotes "they") by Baurus, "Only a true heir of the Blood can wear it, they say."
However, it is preferred to have someone closer to the original line. After Uriel IV dies, it is quoted, "Andorak, Uriel IV's son, was disinherited by vote of Council, and a cousin more closely related to the original Septim line was proclaimed Cephorus II by the next year." I personally believe that the more pure-blooded the Emperor, the more in-tune he is with the Gods (such as Uriel VII knowing the signs of the Gods (events of Illiac Bay, Neravarine prophecies, OB crisis---Especially his dialogue at the beginning)
~TK.R