In about 516 BC the powerful Achaemenian emperor of Persia and son of Hystaspes Darius led an expedition to prove the feasibility of a sea passage from the mouth of Indus to Persia. Under the command of Skylax of Karyanda in Karia a fleet sailed from Punjab in the Gandhara country to the sea reaching the Indian ocean. Darius thus annexed the Indus valley and formed the twentieth satraphy of the person empire. It also included parts of Punjab. The twentieth satraphy was considered to be the richest and most populous of the Persian Empire. The Kharoshti Alphabet, derived from the Aramaic script and written from right to left is said to have been used by the Persians and till the 4^th century AD is said to have been used in the North western frontiers.

 After the death of Bimbisara  in about 494 BC his son Ajatasatru also called Kunika succeeded to the throne of the Magadhan Empire. His rule is said to have lasted for twenty seven years. The imperial city of Pataliputra is said to have been the patronage of Ajathasatru. He also patronised both Mahavira and Buddha. With his aggressive policy of territorial expansion he subdued the Lichchavi's, and the Kosalas. Both these became a part of Magadha. It was during this period that the first buddhist council was held, after the death of Buddha in 478 BC.

Ajathasatru  was succeeded by his son Darsaka. Udayabhadra who built the city of Kusumapura on the banks of the Ganges, away from the Patilaputra. He was succeeded by Anusuddha and Munda. This period witnessed the act of patricide which provoked the people to elect Sisunaga, a minister as the king thus ending the dynasty of rule incepted by Bimbisara. After having subdued the kingdoms and republics of the east Magadha was its height of power. 

The period after Udayabadra till the advent of the Mauryas embraces the period of two generations when Nandivardhana succeeded to the Magadha Empire. Coming under the Saisunaga dynasty Nandivardhana and Mahanandan were the last two of the ten rulers. Nandivardhana is regarded as the inaugurator of the Nanda Era. 

Mahapadma Nanda became king at the age of 20 in 403 BC. The territories of the Nandas included Western Deccan  and northern Mysore. After him the rule of his eight sons follows the last being a contemporary of Alexander. The Nandas were rich but owing to their low origin they were unpopular Dhana Nand was the last son of Mahapadma  Nanda who was overthrown by Chandragupta Maurya with the help of Chanakya in about 25 BC.