Influences from he West.

The life of the Buddha might have been consigned to the dustbin of history as little was heard of  the localised sect in the kingdom of Maghada for two hundred years or so, but the West was spreading its influence Eastwards and routes were opening up by commerce and conquest..

The extent of the Mauryan Empire under Ashoka

The greatest upheaval in the North was the conquest of a large area by Alexander the Great, who had become King of Macedonia, leader of the Greeks, overlord of Asia Minor and Pharaoh of Egypt and 'great king' of Persia at the age of 25. In 500 BCE the Persian King, Darius, had invaded the Indus Valley but the Greeks conquered Persia and he got no further. In 326 Alexander’s armies took a large area of the North, defeating the local ruler, Porus.  By the time the European and Paurava armies faced each other across the banks of the river Jhelum in the Punjab, Alexander’s troops were weary after a long campaign and some hard-won victories in present day Afghanistan and Pakistan.  The 34,000 Macedonian infantry and 7000 Greek cavalry were aided by the Indian king Ambhi, who was Porus’s rival. Ambhi was the ruler of the neighbouring kingdom of Taxila and had offered to help Alexander on the condition that he would be given Porus’s kingdom.
The large numbers of Indian infantry and the war elephants proved a great trial to the Macedonians, but after a ferocious battle Alexander finally prevailed. His conquests spread to what is today the Punjab, spreading to Jammu and the Himalayas. He made alliances with local rulers, and when he returned to Persia, discouraged and with an exhausted and rebellious force, he left several generals to rule the provinces from his centre, Taxila, now in modern Pakistan. Although his rule was very brief the influence of Greek art and culture was long-lasting. As Macedonia broke up following Alexandra’s death, the Selucid Emperor, Nicator, ruled in his place and held the territories in India. It is possible that the reputation of the growing power of the kingdoms of the East were a further disincentive to Alexander to expand his conquests to the Ganges valleys.
While Alexander was taking territory in the West, Chandragupta  Maurya was taking the Nanda lands
round the Ganges Delta. His ambitions led him further West and he met Nicator in battle and defeated him. The resulting treaty, sealed by a marriage, gave the growing Mauryan Empire most of Alexander’s gains. Chandragupta’s statecraft and administrative talents allowed the Mauryan Empire to spread to encompass most of the Indian peninsular, the first unifying kingdom, ruled from Pataliputra, modern day Patna.

 Ashoka Major Rock Edict, Shahbazgarhi

Chandragupta secured the great Mauryan Empire before abdicating in favour of his son, Bindasura. He inherited an empire which spread from the previous Macedonaian conquests across to present day Bengal and as far South as the borders of Tamil Nadu, with the exception of the Kalinga kingdom, modern Orissa. It was Bindasura’s son, Ashoka, who famously united the whole of the Indian peninsular, apart from the Southernmost kingdoms at the very tip.
In about 260 BCE, before he became emperor, Ashoka waged a ferocious campaign against Kalinga which resulted in the death and exile of over 100,000 people. According to the popular legend, he was so sickened by the cruelty of what he had initiated that he turned against violence and embraced a doctrine very similar to Bhuddism. His many edicts, carved on huge boulders across his empire, spread his doctrine of tolerance and peace.

Ashoka was the first unifying ruler of India. There is no evidence that his great empire stretched as far as Kerala. His carved rock edicts have been found as far south as Karnataka and he was in contact with the Buddhist communities of Sri Lanka, but no evidence of his rule has emerged in Kerala so far. A single reference to the south in Edict 13, that of Kerala-putra, is taken to mean that Ashoka’s rule stretched to the beyond Karnataka, but there is no clear definition of what Kerala-putra actually meant geographically. 

   There is a suggestion that trade links with the north were well developed, so it is reasonable to assume that Ashoka’s legacy reached far into the South. Ashoka’s dates have been reliably calculated to the third century BC. He is credited with spreading the Buddhist philosophy of Dharma throughout India, although he did not seem to be too particular which religion or sect incorporated it into their own beliefs.