Note: the Roman Government, in the early centuries A.D., put out a series of coins commemorating Mt. Gerizim and the temple located on it. The Samaritans consider the temple on Mt Gerizim to be the true temple and not the one in Jerusalem.
The Israeli Antiquities Authority states, "Today we can state with certainty that the first phase of the temple on Mount Gerizim was erected in the middle of the fifth century BCE by Sanballat the Horonite, a contemporary of Ezra and Nehemiah, who lived more than one hundred years before the Sanballat that is mentioned by Josephus. Sanballat from the time of Nehemiah was probably a resident of Hawara (Horon), located at the foot of Mount Gerizim, and was a descendant of the last Israelites who remained in Samaria after the destruction of the city by the Assyrians."
http://www.antiquities.org.il/Article