Era
20th century
7
21st century
6
1989-
3
1900-2002
2
1921-2021
2
1926-2022
2
1930-2002
2
1981-1989
2
Elizabeth II, 1952-2022
2
1819-1861
1
1819-1901
1
1874-1965
1
1880-1965
1
1895-1952
1
1898-1951
1
1898-1978
1
18th century
1
1917-1984
1
1919-1952
1
1929
1
1930-2019
1
1931-
1
1938-
1
1945-
1
1951-
1
1953-2007
1
1954-
1
1960-
1
1979-
1
1989-1993
1
1991-
1
1992
1
2001-
1
2017-2021
1
265-30 B.C.
1
British occupation, 1765-1947
1
Republic, 265-30 B.C.
1
Victoria, 1837-1901
1
approximately 100 B.C.-
1