UnScramble this Word: i r e s f e t n?

Questions

In 1981 Beatle ---------- marries actress Barbara Bach.?

In 1987 US Justice Dept bars Austrian Chancellor Kurt ---------- from entering US, due to his aid of Nazi Germany during WW II.?

In 1989 ---------- students take over Tiananmen Square in China.?

In 1442 Edward IV, king of ---------- (1461-70, 1471-83), born.?

In 1686 1st volume of ---------- Newton's "Principia" published.?