Longest reign in Europe
Who
Afonso I Henrique
Where
Portugal ()
When
The longest reign of any European monarch was that of Afonso I Henrique of Portugal who ascended the throne on 30 April 1112 and died on 6 December 1185 after a reign of 73 years 220 days, first as Count and then (after 25 July 1139) as King.

Contrary to press reports following the death of Ranier III, Prince of Monaco on 6 April 2005, he is not the longest-serving monarch in Europe, having become the ruling prince in 1949 - a total of 56 years.