The polity of Pannai was a militant-nation settled by Warrior-Monastics as evidenced by the Temple ruins in the area as it was allied under the Sri-Vijaya Mandala that defended the conflict-ridden Strait of Malacca. The small kingdom traded with and simultaneously repulsed any unlicensed Chinese, Indonesian, Indian or Arab navies that often warred in or pirated the strait of Malacca and, for a small country, they were adept at taking down armadas larger than itself - a difficult endeavour to achieve in the strait of Malacca, which was among the world's most hotly contested maritime choke-point where, today, one half of world trade passes through. The naval power of Pannai was successful in policing and defending the straights of Malacca for the Mandala of Srivijaya until the Chola invasion of Srivijaya occurred, wherein a surprise attack from behind, originating from the occupied capital, rendered the militant polity of Pannai vulnerable from an unprotected assault from the back flank. The Chola invaders eventually destroyed the polity of Pannai and its surviving soldiers, royals and scholars were said to have been secreted-out eastwards. In their 450 years of occupying Sumatra, they refused to be enslaved to Islam, Taoism or Hinduism after the polity's dissolution. The people who stayed behind in Pannai, themselves, have an oral tradition wherein they said that the high-borne scholars, soldiers and nobles of Pannai who refused to swear allegiance to a treacherous invading empire, faithfully followed their kings, the "datus" and "fled to other islands."