Extensive answers to the questions raised in this letter can be found in three books published in the JSP series (Judea and Samaria Publications, volumes 2, 7 and 8), and in additional articles, all in English.
More specifically, the dynasty of governors that ruled Samaria in the Persian period and that originated in the Israelite remnant in Samaria after the Assyrian conquest is and was known by the Assyrian name “Sanballat.” We know of Sanballat in the time of Nehemiah, Sanballat who appears in the papyri from Wadi Daliyeh, Sanballat from the Elephantine letters, and Sanballat from the time of Alexander the Great. During the course of the Persian period, which extended for some 200 years, there were undoubtedly additional governors by this name.
The questions that occupied scholars until the beginning of the excavations at Mt. Gerizim were: When was the temple on Mt. Gerizim built? And when did the marriage of Sanballat’s daughter to the grandson, or brother, of the High Priest in Jerusalem take place—in the time of Nehemiah (Nehemiah 13:28) or in the time of Alexander, a century later? The answers to these two questions leads us to the resolution of the central issue regarding Samaritan-Jewish relations, namely, when did the great split between them occur? It may reasonably be assumed that the establishment of the temple on Mt. Gerizim marked the parting of the ways between them: The Jews prayed in and sanctified Jerusalem, while the Samaritans prayed at and ascribed holiness to Mt. Gerizim.
The archaeological excavations at Mt. Gerizim proved unequivocally that the temple on the mount was built in the middle of the fifth century B.C.E., that is, most likely before Nehemiah’s arrival in 445 B.C.E. The dating of the temple is based on the architecture that is dated with certainty to the Persian period, the carbon-14 tests that were conducted on hundreds of thousands of the bones of sacrifices from kosher animals that were discovered in the sacred precinct, and the pottery vessels and coins that are dated to the fifth century B.C.E. An additional temple was built over the first temple during the reign of Antiochus III, c. 200 C.E.
The testimonies from the fifth century categorically indicate that Josephus erred in his attribution of the temple to the time of Alexander the Great, immediately following his conquest of the Land of Israel. The rift between the Samaritans and the Jews occurred upon the establishment of the temple on Mount Gerizim, and therefore it would be difficult to accept Josephus’s statement regarding the marriage of Nicaso, Sanballat’s daughter, to the brother of the High Priest in Jerusalem. It would seem that Nehemiah’s words on this question are correct. We do not know on what sources Josephus relied besides the Book of Nehemiah. Josephus wrote the history of that period some 500 years later, and his testimony is unreliable.
The question of why Nehemiah makes no mention of this temple troubled many researchers in the past. The answer is that the Jewish sources ignored the existence of the temple on Mt. Gerizim, even after the destruction of Mt. Gerizim and Jerusalem. The establishment of temples was not a rare occurrence in the Persian period—for instance, the temple that the Jews built in Elephantine, and a temple might also have been established in Babylonia.