Emperor Gaozu of Tang
In 621, Wang, facing military pressure from Li Shimin, the son of Emperor Gaozu of Tang, surrendered. Li Shimin set up headquarters at Luoyang, and Su requested an audience with him, but stated that he was too old to bow to Li Shimin. Li Shimin sent back a messenger to rebuke him for bowing to Li Mi and Wang and refused to meet him. Su subsequently went to the Tang capital Chang'an and sought an audience with Emperor Gaozu, and was similarly rebuked and not given an office. He died in 623.