query: Which English monarch has had the longest reign?
passage: List of monarchs in Britain by length of reign
Queen Elizabeth II became the longest-reigning British monarch on 9 September 2015 when she surpassed the reign of her great-great-grandmother Victoria.[1][2] On 6 February 2017 she became the first British monarch to celebrate a Sapphire Jubilee, commemorating 65 years on the throne.
passage: Kangxi Emperor
The Kangxi Emperor's reign of 61 years makes him the longest-reigning emperor in Chinese history (although his grandson, the Qianlong Emperor, had the longest period of de facto power) and one of the longest-reigning rulers in the world.[1] However, since he ascended the throne at the age of seven, actual power was held for six years by four regents and his grandmother, the Grand Empress Dowager Xiaozhuang.