Ruby jubilee

A ruby jubilee marks a 40th anniversary.

Ruby jubilees in recent history

Monarch	Year of Ruby Jubilee
Günther Friedrich Karl II, Prince of Schwarzburg-Sondershausen	1875
Emperor Pedro II of Brazil	1881
Frederick Francis II, Grand Duke of Mecklenburg-Schwerin	1882
Ernest II, Duke of Saxe-Coburg and Gotha	1884
George Tupou I of Tonga	1885
George Victor, Prince of Waldeck and Pyrmont	1885
Franz Joseph I Emperor of Austria & King of Hungary	1888
Peter II, Grand Duke of Oldenburg	1893
Charles Alexander, Grand Duke of Saxe-Weimar-Eisenach	1893
Ernst I, Duke of Saxe-Altenburg	1893
Johann II of Liechtenstein	1898
Frederick I, Grand Duke of Baden	1898
Heinrich XXII, Prince Reuss of Greiz	1899
Frederick William, Grand Duke of Mecklenburg-Strelitz	1900
King Norodom of Cambodia	1901
Emperor Gojong of Korea	21 Jan 1904
King Carol I of Romania	10 May 1906
George II, Duke of Saxe-Meiningen	1906
King Chulalongkorn (Rama V) of Siam	1908
Emperor Meiji of Japan	1908
King Alfonso XIII of Spain	1926^[1]
Sobhuza II of Swaziland	1939
King Gustaf V of Sweden	1947
Sālote Tupou III of Tonga	1958
Emperor Showa of Japan	Dec 1966
Franz Joseph II of Liechtenstein	1978
King Bhumibol Adulyadej (Rama IX) of Thailand	1986^[2]
Prince Rainier III of Monaco	1989
Queen Elizabeth II of the United Kingdom and the other Commonwealth Realms	6 February 1992^[3]
King Hussein of Jordan	11 August 1992
Tāufaʻāhau Tupou IV of Tonga	16 December 2005
Sultan Hassanal Bolkiah of Brunei	5 October 2007
Sultan Qaboos bin Said of Oman	23 July 2010
Queen Margrethe II of Denmark	14 January 2012^[4]^[5]
King Carl XVI Gustaf of Sweden	15 September 2013^[6]