The first stamp with the image of the king Juan Carlos I of Spain was issued on December 29, 1979. The last are those above, issued on January 1, 2013 (data from here).
Yesterday, when I heard that the king of Spain abdicated the throne in favour of his son, my first thought was: "When are they going to issue stamps with the new king?". And my second thought: "Wow, I have really a snail mail mind!".