For 10 points, name this two-faced Roman god of beginnings and gateways, the namesake of the Gregorian calendar's first month.
After emigrating from Thessaly this figure was welcomed by Camese, with whom he fathered Tiberinus. Other children include Fons by the nymph Juturna, and with the nymph Carna he was the progenitor of a line of Kings of Alba Longa. Originally a King of Latium, he was deified by Numa Pompilius. In one story he halted a Sabine attack by causing a hot spring to erupt, which led to the doors of his temple being opened in all further times of war. For 10 points, name this two-faced Roman god of beginnings and gateways, the namesake of the Gregorian calendar's first month.
After emigrating from Thessaly this figure was welcomed by Camese, with whom he fathered Tiberinus.
{Janus}