Congratulations to HM The Queen and HRH the Duke of Edinburgh on their 70th anniversary!
Off the top of my head, I can't think of any other European royal
couples who were married for 70 years, though the remarkable Prince
Takahito (1915-2016) and Princess Yuriko (b 1923) of Japan were married
for 75 years (1941-2016).
King Michael (b 1921) & Queen Anne (1923-2016) of Romania were married for 68 years (1948-2016).
Prince Henri (1908-1999) & Princess Isabelle (1911-2003), Count
& Countess of Paris, were also married for 68 years (1931-99), but
had separated in 1986.
Juliana (1909-2004) & Prince Bernhard (1911-2004) of the Netherlands
were married for 67 years (1937-2004, her death), but had also
King Bhumibol Adulyadej (1927-2016) & Queen Sirikit (b 1932) of Thailand were married for 66 years (1950-2016).
Prince Alfonso (1841-1934) & Princess Antonia (1851-1938) of the
Two Sicilies, Count & Countess of Caserta, were married for nearly
66 years (1868-1934).
Emperor Hirohito (1901-1989) & Empress Nagako (1903-2000) of Japan were married for 64 years (1924-89).
Grand Duke Friedrich Wilhelm (1819-1904) and Grand Duchess Augusta
(1822-1916) of Mecklenburg-Strelitz were married for nearly 61 years
Prince Pedro of Brazil (1913-2007) & Princess
Esperanza of the Two Sicilies (1914-2005) were married for 60 years
King Nikola I (1841-1921) & Queen Milena (1847-1923) of Montenegro were married for 60 years (1860-1921).