The arrival of the great Arahat Bhikkuni Sangamitta to Sri Lanka and the found chon of establishment of the order of the nuns (Bhikkuni Sasanaya) took place on Unduvap Poya Day. Further on this Unduvap Poya Day, she brought with her a sapling of the Sacred Jayasrimaha Bodhi tree from Buddhagaya. Where Prince Siddhartha attained Enlightenment. The Bo-sapling was brought to Sri Lanka from India through the Expressway or Highway constructed from Dambakola Patuna, a sea port in the North of Sri Lanka, to Anuradhapura, with all pomp and glamour with respect of honour befitting to this event. The Bo-sapling was presented to the ruler of Sri Lanka, Devanampiyatissa.

The advent of Buddhism to Sri Lanka took place on Poson Poya Day with the arrival of Arahat Mahinda, son of Emperor Asoka and the foundation for the establishment of the order of nuns began with the coming of Arahat Mahinda’s sister Arahat Sangamitta Thera to Sri Lanka.

Pretty, pleasant and charming Princess Sanghamitta at the age of 16, married a Prince namely Aggribrahama. They were blessed with a son. They named him Sumana. Emperor Asoka’s brother Prince Tissa entered the Buddhist order. He was followed by Prince Aggribrahama. After he entered the Buddhist order, the little Prince Sumana too entered the Buddhist order at the age of seven (7) years.

The turning point of Sanghamitta’s life was, that she too decided to enter the sasana as a Bhikkuni. She entered the order of nuns, under the guidance of two elderly nuns, namely Ayupali and Dhammapali.

At the age of 61 years, during the reign of King Uttiya, Arahat Therani Sanghamitta passed away. Sri Lankans are ever grateful to these two Arahat Mahinda and Theri Sanghamitta, who were responsible in making Sri Lanka the “Dhammadeepa”.

These two events changed the entire course of Sri Lanka’s history. With these two significant events, there sprang up a new society, economy, culture, arts, crafts and a proud Buddhist civilization and Buddhist Literature. Mahamegha Park at Anuradhapura-Mahavihara became the citadel Buddhism, which was to be official religion of Sri Lanka. The present day the city of Anuradhapura and its ruins, the massive stupas, edifies, the tanks are a silent tribute to Arahat Mahinda and Sanghmitta Theri. No visit by an foreign delegation, envoys, diplomats has created such an impact on the lives of Sri Lankans as the visits of Arahat Mahinda and Arahat Sanghamitta. It was the dawn of a new social, cultural and spiritual revolution in the island. After Sanghamitt’s arrival, Buddhism was deeply rooted. This took place on Unduvap Poya Day, and the Buddhists pay homage to Sanghamitta specialisation this day. Anuradhapura is the centre of attraction on this Unduvap Poya Day. Many devotees observe sil at the Jayasri Maha Bodhi and Ruwanveliseya premises.

The spread of Buddhism helped Sri Lankans to mould their character. It helped them to be compassionate, kind hearted men and women. They followed the five precepts (abstain from destroying living beings, abstain from taking things not given, abstain from sexual misconduct, abstain from fame speech, abstain from taking anything that causes introduction or heedlessness). Buddhism is not only a great religion and a philosophy it is also a way of life.

King Devanampiyatissa’s queen Anula and about and the ladies of the Royalty and some women folk in Sri Lanka were keen to enter the order, informed Arahat Mahinda Thero about their desire. Arahat Mahinda advised the king to invite her sister Sanghamitta Theri (nun) to Sri Lanka to establish the order of the nuns.

Bhikkuni sasanaya or order of the nuns was first established by Maha Prajapathi Gotathi – foster mother of Siddhartha Gautama Buddha. The blessed one, elevated Maha Prajapathi Gotami to the rank of the foremost nun. Later, Buddha selected Khema and Uppalavanna as the two chief disciples like Sariputta and Moggallana.

According to the historical evidence available eight (8) under of Sanghamitta, eleven (11) nuns including the Sri Lankan Ambassador Artitta members of various castes, who were specialists in various fields of arts and crafts too accompanied Sanghamitta. The delegation was headed by Bodhigupta. They brought eight Bo-saplings. “Ashtapala Bodhis”. They were distributed to eight provinces. This symbolised one country-one rule and it took place on Unduvap Pura Pasalosvaka Poya Day. Therefore this poya is important to Sri Lankans.

Renouncing a royal life Princess Sanghamitta, entered the order at the age of eighteen (18) years. It should be mentioned here, the name of Sanghamitta and Unduvap Poya were inseparable. She was a role-model for all woman folk in Sri Lanka.

Never did Arahat Mahinda or his sister Sanghamitta Theri, used any iniquitous unjust methods in spreading Buddha Dhamma in Sri Lanka. The only weapon they wielded was that of universal love and compassion. Buddhism is so appealing to the modern world. Once the great physist – Albert Eienstine (1879)-1955 stated “if there is any religion in the world that would cope with modern scientific needs it would be Buddhism”.