I  have mentioned several times now, that there is evidence that Sargon  and Sennacherib are indeed the same person. I do not claim that their  reigns overlapped each other, but I believe that Sargon (the Assyrian  name) came to be called Sennacherib (the Babylonian name) much as  Tiglathpileser (Assyrian) came to be called PUL by the Babylonians. I  have given evidence from the Eponym and Assyrian King lists; and I have  given evidence from scripture. But there is more.
This part is  just a few snippets from from Damien Mackey’s internet article called  ‘Sargon is Sennacherib’. IT is a fairly long article, but I wanted you  all to see at least a couple of his major points. The rest of this  section is all from his article:
What had struck me, however, was  that Sargon's 12th and 15th year campaigns were worded very similarly to  Sennacherib's first two campaigns.
Sargon: "In my twelfth year of  reign, Marduk-apal-iddina [Merodach-baladan] and Shuturnahundu, the  Elamite ... I ... smote with the sword, and conquered ..."
Sennacherib:  "In my first campaign I accomplished the defeat of Merodach-baladan ...  together with the army of Elam, his ally ....".
And:
Sargon:  "Talta, king of the Ellipi ... reached the appointed limit of life ...  Ispabara [his son] ... fled into ... the fortress of Marubishti, ...  that fortress they overwhelmed as with a net. ... people ... I brought  up."
Sennacherib: "... I turned and took the road to the land of  the Ellipi. ... Ispabara, their king, ... fled .... The cities of  Marubishti and Akkuddu, ... I destroyed .... Peoples of the lands my  hands had conquered I settled therein". Added to this was the  possibility that they had built their respective 'Palace Without Rival'  close in time, because the accounts of each were worded almost  identically [2]. Eric Aitchison alerted me to the incredible similarity  in language between these two accounts: Sargon: "Palaces of ivory,  maple, boxwood, musukkani-wood (mulberry?), cedar, cypress, juniper,  pine and pistachio, the "Palace without Rival"2a), for my royal abode  .... with great beams of cedar I roofed them. Door-leaves of cypress and  maple I bound with ... shining bronze and set them up in their gates. A  portico, patterned after a Hittite (Syrian) palace, which in the tongue  of Amurru they call a bit-hilanni, I built before their gates. Eight  lions, in pairs, weighing 4610 talents, of shining bronze, fashioned  according to the workmanship of Ninagal, and of dazzling brightness;  four cedar columns, exceedingly high, each 1 GAR in thickness ... I  placed on top of the lion-colossi, I set them up as posts to support  their doors. Mountain-sheep (as) mighty protecting deities, I cunningly  constructed out of great blocks of mountain stone, and, setting them  toward the four winds ... I adorned their entrances. Great slabs of  limestone, - the (enemy) towns which my hands had captured I sculptured  thereon and I had them set up around their (interior) walls; I made them  objects of astonishment". Sennacherib: "Thereon I had them build a  palace of ivory, maple, boxwood, mulberry (musukannu), cedar, cypress  ... pistachio, the "Palace without a Rival"2a), for my royal abode.  Beams of ceda .... Great door-leaves of cypress, whose odour ... I bound  with shining copper and set them up in their doors. A portico,  patterned after a Hittite (Syrian) palace, which they call in the  Amorite tongue a bit-hilani, I constructed inside them (the doors) ....  Eight lions, open at the knee, advancing, constructed out of 11,400  talents of shining bronze, of the workmanship of the god Nin-a-gal, and  full of splendour ... two great cedar pillars, (which) I placed upon the  lions (colossi), I set up as posts to support their doors. Four  mountain sheep, as protecting deities ... of great blocks of mountain  stone ... I fashioned cunningly, and setting them towards the four winds  (directions), I adorned their entrances. Great slabs of limestone, the  enemy tribes, whom my hands had conquered, dragged through them (the  doors), and I set them up around the walls, - I made them objects of  astonishment".
……
Conventional Theory's Strengths
(i) Primary
I can find only two examples of a primary nature for the conventional view.
By  far the strongest support for convention in my opinion is Esarhaddon's  above-quoted statement from what is called Prism S - and it appears in  the same form in several other documents as well - that he was 'son of  Sennacherib and (grand)son of Sargon'. Prism A in the British Museum is  somewhat similar, though much more heavily bracketted [6]:
[Esarhaddon,  the great king, the mighty king, king of the universe, king of Assyria,  viceroy of Babylon, king] of [Sumer] and Akkad, [son of Sennacherib,  the great king, the mighty king], king of Assyria, [(grand)son of  Sargon, the great king, the mighty king], king of Assyria ....
The  first document, Prism S, would be enough to stop me dead in my tracks,  were it not for other evidences in support of my proposed merger.
The  other, quasi-primary evidence is in regard to Sennacherib's accession.  One reads in history books of supposed documentary evidence telling that  Sargon was killed and that Sennacherib sat on the throne. Carl Olaf  Jonsson gives it, bracketed again, as follows [7]:
For the eponym  Nashur(a)-bel (705 BC) one of the Eponym Chronicles (Cb6) adds the note  that the king (= Sargon) was killed, and that Sennacherib, on Ab 12,  took his seat on the throne.
What one notices in all of the above  cases of what I have deemed to be primary evidence is that bracketting  is always involved. Prism S, the most formidable testimony, has the word  "(grand)son" in brackets. In Prism A, the entire titulary has been  square bracketed, which would indicate that Assyriologists have added  what they presume to have been in the original text, now missing. And,  regarding Sennacherib's accession, Jonsson qualifies the un-named  predecessor king with the bracketted "(= Sargon)".
It was  customary for the Assyrian kings to record their titulary back through  father and grandfather. There are two notable exceptions in neo-Assyrian  history: interestingly, Sargon and Sennacherib, who record neither  father nor grandfather. John Russell's explanation for this omission is  as follows [8]:
In nearly every other Assyrian royal titulary, the  name of the king was followed by a brief genealogy of the form "son of  PN1, who was son of PN2," stressing the legitimacy of the king.
As  Tadmor has observed, such a statement never appears in the titulary of  Sennacherib. This omission is surprising since Sennacherib was  unquestionably [sic] the legitimate heir of Sargon II. Tadmor suggests  that Sennacherib omitted his father's name either because of disapproval  of Sargon's policies or because of the shameful manner of Sargon's  death ....
This may be, but it is important to note that Sargon  also omitted the genealogy from his own titulary, presumably because,  contrary to this name (Sargon is the biblical form of Šarru-kên: "the  king is legitimate"), he was evidently not truly the legitimate ruler.  Perhaps Sennacherib wished to avoid drawing attention to a flawed  genealogy: the only way Sennacherib could credibly have used the  standard genealogical formulation would have been with a statement such  as "Sennacherib, son of Sargon, who was not the son of Shalmaneser", or  "who was son of a nobody", and this is clearly worse than nothing at  all.
That there was some unusual situation here cannot be doubted.  And the bracketing that we find in Esarhaddon's titulary may be a  further reflection of it. By contrast, Esarhaddon's son, Ashurbanipal,  required no such bracketing when he declared: I am Assurbanipal ...  offspring of the loins of Esarhaddon ...; grandson of Sennacherib ..."  [9].

 
