Who is the only British monarch to have served longer than Queen Elizabeth II?

Queen Victoria, who was Elizabeth's great-great grandmother, reigned from June 20, 1837 until her death on January 22, 1901 -- a total of 63 years and seven months. Elizabeth, who has reigned more than 60 years (from February 6, 1952 to the present), can surpass Victoria's longevity record if she is still Britain's monarch on September 10, 2015.