皇

Top 白 — pictograph of a thumb or, in older readings, a flame above a candle, giving the meanings 'white, bright, dazzling.' The radical anchor for 皇. Carries the imagery of brilliance: an emperor was traditionally seen as radiant, the brightest figure in the realm. Same family: 百 hundred, 的 of, 皓 bright.

Bottom 王 — three horizontal lines (heaven, humanity, earth) joined by one vertical, picturing the king as connector of all three realms. Beneath 白 it gives 'shining king' — a ruler above ordinary kings. The character was reserved for the supreme sovereign after Qin Shi Huang adopted 皇帝 as the imperial title in 221 BCE.