The Mauryan Empire

Conquests of the Mauryan Empire, c.324-261 BC: The Mauryan Empire was the first power to unite most of the Indian subcontinent, and at its peak stretched from Afghanistan in the north-west, east almost to the mouth of the Ganges and south as far as modern Mysore
Seleucus I Nicator's invasion of India (c.306-303 BC) was one of a series of obscure campaigns fought by Seleucus in an attempt to gain control of the eastern part of his recently regained kingdom
The conquest of Kalinga of c.271-261 BC was the only aggressive war fought by the third Mauryan emperor, Ashoka, and the suffering he saw during this war helped turn the Emperor away from violence and towards a more peaceful path.

Chandragupta Maurya (fr.c.325-290 BC) was the founder of the Mauryan Empire, the first great power to dominate the Indian sub-continent.
Bindusara (fr.298-273 BC) was the second ruler of the Mauryan Empire, and may have been responsible for extending the empire into southern India.
Ashoka (fl.269-232 BC) was the third and possibly greatest ruler of the Mauryan Empire, best known for renouncing aggressive war and his efforts to spread Buddhism.