Era
20th century
140
19th century
72
1900-1999
55
1838-1918
25
18th century
22
1800-1899
17
Revolution, 1789-1799
16
1800-1859
13
1805-1859
13
1795-1881
11
1933-1945
10
1945-
10
1737-1794
9
Empire, 284-476
9
To 1500
9
1875-1950
8
1904-2005
8
Revolution, 1775-1783
8
1945-1989
7
16th century
6
17th century
6
1901-1989
6
1939-1945
6
Civil War, 1861-1865
6
1728-1814
5
1800-1999
5
1834-1902
5
1874-1948
5
1908-1999
5
1915-2009
5
1917-2007
5
1918-1999
5
Empire, 30 B.C.-476 A.D.
5
approximately 1090-1143
5
1609-1674
4
1700-1799
4
1789-1815
4
1798-1874
4
1800-1837
4
1866-1934
4
1868-
4
1900-1979
4
1903-2005
4
1918-
4
German occupation, 1940-1945
4
Stuarts, 1603-1714
4
To 1066
4
To 146 B.C.
4
1332-1406
3
1478-1557
3
more ...