Who was the first head of state (or heir) to be killed by assassin's bullet (i.e. using a gun)?

by XIMADUDE

I am think Archduke Ferdinand but did not know for certain.

lu619

You're out by over 300 years... Unless anyone knows of an earlier case, I'd say it was William I of Orange, also known as William the Silent, assassinated 10th July 1584.

Although, checking the Wikipedia for that I find that James Stewart, Earl of Moray and Regent for the young King James VI of Scotland was shot to death in 1570- apparently the first firearm assassination ever, though not of an actual head of state.