Elizabeth II is the longest-lived and longest-reigning British monarch, the longest-serving female head of state in world history, the world's oldest living monarch, longest-reigning current monarch, and oldest and longest-serving current head of state. When her father died in February 1952, Elizabeth, then 25 years old, became Head of the Commonwealth and Queen regnant of seven independent Commonwealth countries. Significant events have included her coronation in 1953 and the celebrations of her Silver, Golden, and Diamond Jubilees in 1977, 2002, and 2012, respectively. In 2017, she became the first British monarch to reach a Sapphire Jubilee. This is a commemorative crown from her Silver Jubilee in 1977.