There existed in ancient Indian society during the lifetime of Sakyamuni
Buddha over 2,500 years ago a caste system comprising priests, the
military and ruling, farmers and traders, and serfs.
The fourfold caste system was uber definitive, disallowing trespassing
of any form. The Buddha in the course of his lifetime had undertaken to
advocate equality among the castes. For, class distinction ultimately not
to be, all living beings possess the Buddha-nature.