The Sarnath pillar, originally with the Lion Capital of Asoka erected atop, marks the site of the first sermon of the Buddha, where he taught the Dharma to five monks. The pillar bears one of the Edicts of Ashoka, an inscription against schism within the Buddhist community, which reads "No one shall cause division in the order of monks".
The pillar was originally a column surmounted by the "Lion capital of Asoka" presently at display at theSarnath Museum, which consists of a canopy representing an inverted bell-shaped lotus flower, a short cylindrical abacus where alternate four 24-spoked Dharma wheels with four animals (an elephant, a bull, a horse, a lion in this order), and four lions facing the four cardinal directions. The four animals are believed to symbolize different steps of the Gautama Buddha's life:
The Elephant represents the Buddha's conception in reference to the dream of Queen Maya of a white elephant entered her womb.
The Bull, according to Foucher, represents the birth of the Buddha, as it happened during the month of Vaicakha (April-May), known to Buddhists as Vesak, under the zodiacal sign of the Taurus, during the full moon. The enlightenment and passing of the Buddha also occurred during the Taurus full moon. The bull is also the symbol of Shiva.
The Horse represents Kanthaka, the horse the Buddha rode for his Great Departure from palatial life.
The Lion represents the attainment of Buddhahood.
The four animals may also represent lesser Hindu deities as they existed at the time, and/or possibly how they were under the service of Buddha. Other sources also mention the four different animals symbolizing the four great rivers of the world, which are mentioned in Indian creation myths.
The four lions surmounting the capital symbolize the kingship of the Buddha and his rule over the four directions.
There are also non-religious interpretations to the symbolism of the pillars, describing the four lions as the symbol of Ashoka's rule over the four directions, the wheels as symbols of enlightened rule (Chakravartin), and the four animals as symbols of four surrounding territories of India:
the Lion of the north.
the Elephant of the east.
the Bull of the south.
the Horse of the west.
This secular interpretation is rather contradicted by the presence of the Edicts, which tend to make Ashoka's pillars a vehicle of religious proselytism rather than just a symbol of royal power.