However, recent archaeological finds at Edfu could indicate that the Hyksos 15th dynasty was already in existence at least by the mid-13th dynasty reign of king Sobekhotep IV. In a recently published paper in "Egypt and the Levant", Nadine Moeller, Gregory Marouard and N. Ayers discuss the discovery of an important early 12th dynasty Middle Kingdom administrative building in the eastern Tell Edfu area of Upper Egypt which was in continual use into the early Second Intermediate Period until the 17th dynasty, when its remains were sealed up by a large silo court. Fieldwork by Egyptologists in 2010 and 2011 into the remains of the former 12th dynasty building which was also used in the 13th dynasty led to the discovery of a large adjoining hall which proved to contain 41 sealings showing the cartouche of the Hyksos ruler Khyan together with 9 sealings naming the 13th dynasty king Sobekhotep IV. The preserved contexts of these seals shows that Sobekhotep IV and Khyan were most likely contemporaries of one another. This could mean that the 13th dynasty did not control all of Egypt when Sobekhotep IV acceded to power, and that there was a significant overlap between the 13th and 15th dynasties since Sobekhotep IV was only a mid-13th dynasty ruler; although one of its most powerful kings. Therefore, Manetho's statement that the Hyksos 15th dynasty violently replaced the 13th dynasty could be a piece of later Egyptian propaganda. Rather, the 13th dynasty's authority must have been collapsing throughout Egypt in its final decades and the Hyksos state in the Delta region simply took over Memphis and ended the 13th dynasty's kingdom. However, this analysis and the conclusions drawn from it are rejected by Egyptologist Robert Porter, who argues that Khyan ruled much later than Sobekhotep IV (a gap of c. 100 years exists between the two in conventional chronologies) and that the seals of a pharaoh were used long after his death. Thus the seals of Sobekhotep IV might not indicate that he was a contemporary of Khyan.