Many Buddhist symbols should be considered within the culture of the people who follow them. Therefore, many from the earlier symbols concern to ancient India and could be found in Hinduism also, though perchance on a somewhat different meaning.
The historical Buddha lived about the 6th century B.C., but no Buddhist artifacts is known from before the 3rd century B.C. In scriptures, it’s noted that the Buddha sometimes used images like ‘Wheel of Life’ to exemplify the teachings. The 1st archeological evidence, mainly of ornamental stone carvings, occurs from the time of Emperor Ashoka (273-232 B.C.), who converted to Buddhism and then made Buddhism a popular religion in India and in the nearby countries .
In the 2nd century B.C. people started to excavate Buddhist monasteries in rocks, creating a big amount of art work to hold up the ages. Probably the earliest distinctive Buddhist monument is stupa, which was frequently specially decorated. The first genuine Buddha images appeared around the 1st century B.C., so till then the artwork was mostly symbolic in nature.
With appearance of the Buddhist Tantra around the 6th century, a new artwork and symbolism appeared, as imagination and visualization form a major technique of meditation practices. From this moment, a pantheon of deities and protectors appeared, together with a immense collection of symbolic items, like the vajra and the bell, mandalas etc. This tradition was mainly kept up within so-called ‘Tibetan Buddhism’.
Since the making of humanlike images of the Buddha was believed sacrilegious for a long time, Buddhist visual art produced an detailed vocabulary of symbolic and iconic forms of expressions. A big variety of Buddhist symbols was found in temples and in Buddhist visual artwork and literature. The lotus, the wheel, and the stupa could be seen in virtually every Buddhist temple. One might interpret these symbols as visual mantras. Contemplating these figures is a part of a meditation practice to build inner contact with the aspect that has represented.
Picture: Tashi Dhargye - The Eight Auspicious Signs, Combined Form