Janus,
in Roman
religion, the animistic spirit of doorways (januae) and
archways (jani). Janus and the nymph Camasene were the parents of
Tiberinus, whose death in or by the river Albula caused it to be renamed Tiber.
The worship of
Janus traditionally dated back to Romulus and
a period even before the actual founding of the city of Rome. There were
many jani (i.e., ceremonial gateways) in Rome;
these were usually freestanding structures that were used for
symbolically auspicious entrances or exits.
Particular superstition was attached to the departure of a Roman army, for
which there were lucky and unlucky ways to march through a janus.
The most famous janus in Rome was the Janus Geminus,
which was actually a shrine of Janus at the north side of the Forum. It was a
simple rectangular bronze structure with double doors at each end.
Traditionally, the doors of this shrine were left open in time of war and were
kept closed when Rome was at peace. According to the Roman historian Livy, the gates were
closed only twice in all the long period between Numa
Pompilius (7th century BC)
and Augustus (1st
century BC).
Some scholars
regard Janus as the god of all beginnings and believe that his association with
doorways is derivative. He was invoked as the first of any gods in
regular liturgies. The beginning of the day, month, and year, both calendrical
and agricultural, were sacred to him. The month of January is named for him,
and his festival took place on January 9, the Agonium. There were several
important temples erected to Janus, and it is assumed that there was also an
early cult on the Janiculum, which the ancients took to mean “the city of
Janus.”
Janus was
represented by a double-faced head, and he was represented in art either with
or without a beard. Occasionally he was depicted as four-faced—as the spirit of
the four-way arch. (Source:
https://www.britannica.com/topic/Janus-Roman-god)