Vajapeya

Along with the Rajasuya, one of the
two most famous of the Vedic sacrifices.
The Vajapeya sacrifice was essentially
intended to provide an established
king with continuing strength and
vitality, magically rejuvenating him
after a long reign and in the face of
advancing age. In ancient times the
rite was elaborate and entailed the
sacrifice of animals; when it is
performed in modern times it is
performed in one day, and the animal
sacrifice is symbolic.