The Sui was founded in 581 CE by Yang Jian, Emperor Wen of Sui, a talented military leader who was in the process of reunifying China after almost three centuries of division between the Northern ...

For example, Q3(a) in Paper One only asked about Emperor Wen of Sui dynasty and his achievements, whereas Q3(b) focused on Emperor Taizong of Tang, his politics and the situation in the Tang dynasty.