when Vietnam regained independence from China in year 939, we faced many challenges as a new nation. We had a hostile imperial China in the north, and a mighty enemy in the south: the kingdom of Champa.
Champa was a hinduism society, based on caste, slaves and a godlike king. Hinduism had spread from India, over Burma, Thailand, Laos and Cambodia to Champa. The Chams controlled the sea lanes from the South China Sea to Indian Ocean. later they converted to Islam as the new belief became popular and successfully intruded into the Philippines, Malaysia and Indonesia. The Chams launched more 10 invasions into the new founded kingdom of Vietnam.
more than one time, Vietnam was on verge of collapse when the Champ troops conquered Hanoi (three times). with China did nothing to help Vietnam.
the final turn came in year 1471, when Vietnam reached the strength, amassed an army of 300,000 men adopting with best firearms. when the Viet troop arrived the capital of Champa Vijaya, we annihilated the Cham army until the last man and made the population to slaves. The Chams asked China for help, but it was too late.
they started, so they deserved the fate.
if we lost the war, they had made us to slaves.
later in the 1490s, Vietnam started a westward military campaign against Laos, Thailand and Burma. the Viet troop arrived the heartland of Burma Kingdom. the Hinduism eased to spead further in SE Asia. as Vietnam the only country in SE Asia having firearms, nothing could stop Vietnamese advance. Ming China forced Vietnam to withdraw from occupied territories. the 5 year long military campaign came to an end.