Complex sentence: The seal of the province shows the stupa at Phra That Si Song Rak, which was built in 1560 by King Maha Chakrapat of the Ayutthaya kingdom and King Chai Chetha of Lan Xang as a symboil of friendship between the two kingdoms.
Split into simpler sentences: The seal of the province shows the stupa at Phra That Si Song Rak built in 1560. It was built by King Maha Chakrapat of the Ayutthaya kingdom, and King Chai Chetha of Lan Xang, and marked the friendship between the two kingdoms.