In an earlier article on this blog, "Neferura--Heir Apparent" I wrote:
"It is scarcely any wonder, then, in light of the above image, that William Petty, in a couple of articles, has pointed out that there are no unambiguous inscriptions of Thutmose III between his Year 5 and Year 13. Where was he and what was he up to? But, sometime after Year 13, Hatshepsut changed her mind and Thutmose began to appear with her on monuments albeit in a secondary position. Then, in her Year 21, Hatshepsut, herself, becomes absent from the record. Under the circumstances, I have to agree with Petty that Thutmose found it convenient to continue the last regnal date of the woman-king. He may have been the rightful sovereign, but it now seems to me he had been deposed, not merely eclipsed, and was not expected to ever resume his kingship during a certain period."
William Petty's paper in the journal, Ostracon, "Redating the Reign of Hatshepsut" can be found here:
http://www.egyptstudy.org/ostracon/vol12_2.pdf
Upon re-reading this paper, I discovered something that would have made no sense to me had I not been doing the calculations connected to the obelisk inscription of Hatshepsut, described on this blog. There I concluded the progression of the Sothic sighting within the civil calendar showed 32 years had gone by between the end of the reign of Amenhotep I and Year 16 of Hatshepsut, leaving 16 years for the interim rulers. These I apportioned as 13 for Thutmose I and three for Thutmose II.
Now it appears that may be exactly right. William Petty mentioned that the Donation Stela of Senenmut was a perplexing item. Even though it is evidently dated to Year 4 of Thutmose III, "Maatkara", the prenomen of Hatshepsut, is mentioned and the mortuary temple of the queen and Senenmut's tomb are referenced. However, there is ample evidence that neither of these were begun until Year 7, which some regard as the year of the "switch" from Hatshepsut as regent to a ruler with full pharaonic titulary. How is it possible for things not constructed until Year 7 to be mentioned in Year 4? The answer is now obvious.
William Petty suggested the regnal years of Thutmose III and Hatshepsut were "artificially synchronized", but he did not say exactly when. He was correct, in my opinion, but I think my astronomical calculations serve to reinforce the assertion of Petty that, if taken at face value, the Donation Stela implies that Year 4 of Thutmose III was coincidental with Year 7 of Hatshepsut. Therefore when she became a "woman-king"--Hatshepsut did not adopt the regnal count of Thutmose III--exactly. Hatshepsut counted her reign back to the death of her father, Thutmose I, and, in doing so, appropriated or rather obliterated the entire three-year rule of her half-brother, Thutmose II. And that is why she asserted the fictitious claim that her father made her his successor when she was still young--so she could not only usurp the throne of her nephew but claim the three regnal years of her dead husband as her own, in addition. That is how Year 4 of Menkheperra became Year 7 of Maatkara--she usurping the entire time that had passed since Thutmose I had "flown to heaven". Even though Thutmose III apparently hung on for yet another year, his Year 5----there is nothing that attests to his kingship for some years afterward.
Once he reappeared on the scene, the year count no longer belonged to Thutmose III. As he was re-instated as a kind of "junior partner" of his aunt, he had no choice but to assume her false regnal count with her and, after she disappeared in her year 21, it was no longer practical to go back three years to his own count as by now hundreds of records were surely in existence using Hatshepsut's dubious reckoning. Since these records had to be referenced in legal disputes, to go back instead of foreward would have resulted in chaos. Doubtless many would disagree with me and say that there were retrospective additions to the Donation Stela--but Petty could not see this. I have not been able to examine the stela, myself. However, one must admit my reasoning addresses the question of why would Hatshepsut wait a full seven years to usurp her nephew's prerogative with the boy or young man growing older every year and ostensibly more firmly ensconced on his throne? Probably she did not wait seven years at all.