Who held the title of the longest reigning monarch until 9 September 2015?

Queen Victoria reigned for over 63 years, from 1837 until her death in 1901. Her reign is known as the Victorian era, a period of great social and industrial change in Britain. Think of inventions like the telephone and the expansion of the British Empire – all happening under Victoria! Before 2015, she held the record as the longest-reigning British monarch. Now, while Elizabeth I was a very important monarch in the 16th century, and Elizabeth II has now surpassed Victoria, it was Victoria who held the record for the longest reign *until* September 9, 2015. Mary, while a significant queen, simply did not reign for a comparable length of time. So, when you think of a long and impactful reign before our current Queen, Victoria is the name to remember.
Think of the queen after whose reign an entire era was named in Britain. She reigned until 1901.