Query: What ethnicity made up the Upper Three Banners?
Context: The yellow, bordered yellow, and white banners were known as the "Upper Three Banners" and were under the direct command of the emperor. Only Manchus belonging to the Upper Three Banners, and selected Han Chinese who had passed the highest level of martial exams could serve as the emperor's personal bodyguards. The remaining Banners were known as the "Lower Five Banners."