Li Shimin spared Wang , but executed a number of his high - level officials .
In 621 , Li Shimin put Luoyang under siege and , after defeating Wang 's ally Dou Jiande the Prince of Xia , forced Wang to surrender .
Li Shimin spared Wang , but executed a number of Wang 's high - level officials .
In 621 , Li Shimin put Luoyang under siege and , after defeating Wang 's ally Dou Jiande the Prince of Xia , forced Wang to surrender .