Most scholarship concerning the date of Herod's death follows Emil Schürer's calculations, which suggest that the date was in or around 4 BCE; this is three years earlier than the previous consensus and tradition (1 BCE). Two of Herod's sons, Archelaus and Philip the Tetrarch, dated their rule from 4 BCE, though Archelaus apparently held royal authority during Herod's lifetime. Philip's reign would last for 37 years, until his death in the 20th year of Tiberius (34 CE), which implies his accession as 4 BCE. Some scholars support the traditional date of 1 BCE for Herod's death. Filmer and Steinmann, for example, propose that Herod died in 1 BCE, and that his heirs backdated their reigns to 4 or 3 BCE to assert an overlapping with Herod's rule, and bolster their own legitimacy. In Josephus' account, Herod's death was preceded by a lunar eclipse and followed by Passover. A partial eclipse best observed from the west coast of Africa, took place on March 13, 4 BCE, about 29 days before Passover. Whilst this eclipse has been suggested as the one referred to by Josephus, there were other eclipses during this period, with proponents of 5 BCE and the two eclipses of 1 BCE occurring January 10, being the most spectacular total lunar eclipse and December 29, another only partial eclipse.