Refers to a Chinese dynasty of the period 589 to 618 CE. During this time northern and southern China were reunited after centuries of separation. ——艺术与建筑索引典

Sui dynasty, Wade-Giles romanization Sui, (581–618 ce), short-lived Chinese dynasty that unified the country after four centuries of fragmentation in which North and South China had gone quite different ways. The Sui also set the stage for and began to set in motion an artistic and cultural renaissance that reached its zenith in the succeeding Tang dynasty (618–907). Its capital was at Daxing, which, during Tang times, changed its name to Chang’an (now Xi’an).——britannica academic  @en