Complex sentence: The eastern Mon including the current royal family of Thailand who themselves are of Mon ancestry assimilated to Thai culture long ago, yet the royal women of the Chankri dynasty perform and keep their Mon heritage alive in the Thai court.
Split into simpler sentences: The eastern Mon include the current royal family of Thailand who are of Mon ancestry. The Mon assimilated to Thai culture long ago, yet the royal women of the Chankri dynasty perform and keep their Mon heritage alive in the Thai court.