Spain went from dictatorship to democracy in three years.
Franco died on 20 November 1975 after 36 years in power. King Juan Carlos I and prime minister Adolfo Suárez opened the system step by step: first free elections in June 1977, a constitution approved by referendum on 6 December 1978. A coup attempt on 23 February 1981, when guards stormed parliament, failed partly due to the king's opposition.
Useful: Transitions tend to succeed when old elites get a place in the new system.
Source: en.wikipedia.org