Misc: What famed romantic spent the last 13 years of his life as a Bohemian librarian?

Questions

In 1955 ---------- model/David Bowie's wife/actress (Star Trek VI), born. ?

In 1957 Monarchy in ---------- abolished in favor of a republic. ?

In 1963 US, ---------- and England sign nuclear test ban treaty. ?

In 1965 Folk-rock begins, ---------- uses electricity at Newport Folk Festival. ?

In 1968 Pope ---------- encyclical On the regulation of birth. ?