Poson Poya Day which falls on June 8 this year, commemorates the advent of Arahant Mahinda, son of Emperor Ashoka of India. Arahant Mahinda introduced to Sri Lanka, Buddha Dhamma, making Poson a festival that is second in significance only to Vesak. Though Poson is celebrated island-wide, the main centre of celebration is Mihinthalaya, Anuradhapura, where Arahant Mahinda delivered his first sermon to King Dewanampiyatissa, the then ruling king of the ancient capital of Anuradhapura.

Emperor Ashoka the Great, the third ruler of the Mauryan Empire, the largest ever in the Indian subcontinent and one of the world’s largest empires at the time, ruled India from 268 BCE to 232 BCE. Emperor Ashoka became a model of kingship in the Buddhist tradition. Previously, he was cruelly efficient in his military ruling in order to expand the empire.

During the expansion of the Mauryan Empire, Ashoka led a war against a feudal state named Kalinga around 261 BCE. It wss considered one of the most brutal wars in world history. The disaster in Kalinga was supreme, resulting in deaths by the thousands and incalculable destruction to property. Sickened by the slaughter he had seen during the war Ashoka decided to terminate the expansion policy and embrace the propagation of dhamma.

Ashoka who was earlier known for his merciless ruling as Chandashoka, came to be known as Dharmashoka from then on. Becoming a fervent patron of Buddhism, Ashoka did his best to propagate the religion, making it the state religion and encouraging Buddhist missionary activities. Ashoka renounced armed conquest adopting the policy ‘conquest by dhamma’.

Ashoka’s patronage of Buddhism was much enduring. He built many stupas, and monasteries and erected pillars on which he ordered inscribed Buddhist religious doctrines. It is said in the Mahavamsa that as a result of Ashoka’s patronage of Buddhism, when he ordered Buddhist missions abroad, he enthusiastically supported the process by sending his own son and daughter as missionaries to Sri Lanka.
Tissa, later Devanampiyatissa was one of the earliest kings of Sri Lanka based at the ancient capital of Anuradhapura from 307 BCE to 267 BCE. Mahavamsa mentions an early friendship between Tissa and Ashoka, qualifying the Sri Lankan king to receive the great gift of Dhamma from India.

According to the Mahavamsa, King Devanampiyatissa was out enjoying a hunt with some 40,000 of his soldiers near the mountain Mihintale. The 3rd Century BCE Mihintale was a thick jungle inhabited by wild animals and was a designated royal hunting ground.
Having come to the foot of Missaka, Devanampiyatissa chased a stag into the thicket, and came across Arahant Mahinda. According to Mahavamsa the great king had been terrified as the thera was misunderstood to be a ‘yakka’, or demon. However, after Arahant Mahinda having declared, ‘Recluses we are, O great King, disciples of the King of Dhamma (Buddha). Out of compassion for you alone have we come here from Jambudwipa’. Devanampiyatissa recalled the news from his friend Ashoka and realised that these were missionaries sent from India.

According to the Mahavamsa, then the king had been questioned by Arahant Mahinda in order to decide whether he is intelligent enough to understand the philosophy of the Buddha. Directing his attention to a tree nearby, Arahant Mahinda asked,

“What is the name of this tree?”
The King answered “This is a mango tree, sir.”
“Are there mango trees other than this mango tree?”
“Yes. There are many other mango trees, sir.”
“Are there other trees beside this mango tree and other mango trees?”
“Yes… There are many other trees that are not mango trees, beside this mango tree and other mango trees, sir.”
“Are there other trees that are not mango trees and other mango trees?”
“Yes…That is this mango tree, sir.”
“Do you have relatives?”
“Yes…I have many relatives.”
“Are there people who are not your relatives?”
“Yes…There are many people who are not my relatives”
“Are there people other than your relatives and non relatives?”
“Yes…That would be me, sir.”
“Good…You are very intelligent and ready to listen to Buddha Dhamma.”
Thence, with Arahant Mahinda having preached Chulla Hatthi Padopama Sutta to the King and his 40,000 men, they converted to Buddhism.

Arahant Mahinda’s Lanka mission was a great success. He found in the country a fertile soil to disseminate the sublime teachings of the Buddha. With royal patronage Buddhism was firmly established in Sri Lanka.

With the establishment of the Bhikku Sasana and with royal patronage all other elements of a civilized society began to emerge with the art of writing, art, architecture, river bank civilizations, religious rituals, and forms of song and dance and literature.