Probably the royal wedding.
It is "a historic event"
It has always been my my understanding that "an" should precede "historical" and "a" before "historic".
There are lots of them including Stonehenge, Windsor Castle, Tower of London, St. Paul's Cathedral.
i was raised by wolves
u were born
who was in that event
golden golden
The Storming of the Bastille
The Crusades
defeat of the spanish armada in 1588
America became a country.
Strauss gatting brearley illingworth hutton