A leap of faith brought five South-east Asian nations together decades ago, giving rise to an unlikely brotherhood in a region rocked by hostilities and strife.
Yesterday, 51 years on, hard-won camaraderie united the leaders of Asean, now a 10-member grouping that has left its mark on the world stage.
Good cheer filled the air as the leaders filed into the Suntec convention centre, after motorcades whisked them through the bustling heart of downtown Singapore.
There, past security checkpoints that had turned the venue for the 33rd Asean Summit into an object of curiosity for tourists and shoppers at nearby malls, waited Prime Minister Lee Hsien Loong. He had handshakes and exuberant greetings for his fellow leaders - many of them now familiar friends.
There was a booming "Your Majesty" for Brunei's Sultan Hassanal Bolkiah, a 30-year veteran of Asean summits.
For Malaysian Prime Minister Mahathir Mohamad - the sole survivor of the old guard of formidable South-east Asian leaders that included PM Lee's father, Singapore's founding PM Lee Kuan Yew - a warm clasp of the hand and respectful nod.
Mrs Lee darted forward, moving away from her husband's side, where she had been greeting the spouses of Asean leaders with cheek kisses, to take the hand of Tun Dr Mahathir's wife.
She would accompany Tun Dr Siti Hasmah Mohamad Ali - who had been with Dr Mahathir yesterday on his whirlwind schedule of commitments - out of the greeting area, hand in hand, heads bent in conversation, before resuming her post.
Asean's leaders are in town for a marathon series of meetings that marks the final milestone of Singapore's one-year chairmanship of the regional grouping.
It will be a time to take stock of Asean's achievements - and discuss how to take the group forward at a time of global upheaval. There was no glitz or glamour, no chandeliers or gold trimming - but as its leaders came face to face once more in a modest convention hall for the summit's opening ceremony, an air of celebration prevailed.
Indonesian President Joko Widodo sang along to a Singapore vocal group's rendition of Secret Garden's You Raised Me Up.
The Asean spirit of regional cooperation and friendship was celebrated, with Ms Erlinda Uy Koe, the chair emeritus of Autism Society Philippines, honoured with the inaugural Asean Prize to recognise an individual or organisation that has promoted intra-Asean collaboration.
PM Lee had, at a meeting of Asean foreign ministers in August, noted the grouping's five founding members took a leap of faith in 1967 when they decided to band together, setting aside "old suspicions and rivalries".
But divides still remain.
Just before the reunion yesterday, Dr Mahathir had told reporters he was disappointed with Myanmar's handling of the Rohingya crisis in Rakhine State. But at the ceremony - as he sat with Myanmar's de facto leader Aung San Suu Kyi to his right, in keeping with the alphabetical order that determines seating - the grouping presented a united, unruffled front.
It was a showcase of Asean's conviction that the grouping is greater than the sum of its parts.
"Each member state has its own strategic outlook, political calculations and national interests. Despite this, Asean has shown that it is still able to work together and find common ground," PM Lee said.
"By coming together in one collective voice, instead of going our separate ways as 10 disparate countries, Asean members have strengthened our standing in the world."