It's tough to be a King sometimes! William II was shot while hunting. Many historians believe that the shooter was his brother, or acting for his brother, the future Henry I. Edward II, on the other hand, was killed after being deposed, on orders of his wife. Richard II and Henry VI were deposed and killed marking the beginning and the end of the House of Lancaster. Charles I was deposed and then beheaded.

Other Kings who were killed include Richard I, shot accidentally by a "friend", Henry V (disappeared and presumed killed with his brother in the Tower of London by Richard III), Richard III who was killed by Henry Tudor who became Henry VII.

Neither William II nor Richard II had any legitimate children. Edward II and Charles I were succeeded by sons. Henry VI was killed just weeks after his son died in battle.

William II, Edward II are believed by most historians to have been homosexual. There were rumors that Richard II was gay as well, but this is less supported by evidence.

The shortest reign of these five Kings was William II who reigned from 1087-1100. Henry VI, by far the longest, reigned from 1422-1471 (with a short break from 1461-1470 during which Edward IV took over). The others held the throne for close to 20 years: Edward II: 1307-1327, and Richard II: 1377-1399, Charles I: 1625-1649.

More Info: en.wikipedia.org