British youth are ignorant of their own history with fewer than half questioned knowing Sir Francis Drake defeated the Spanish Armada, according to a poll.
Some thought Tolkien's Gandalf defeated the Spanish Armada
Some 13% of 16 to 24-year-olds credited CS Forester's fictional Horatio Hornblower, while 6% thought it was Tolkien's wizard Gandalf.
Even the over-65s fared little better on some questions, with 22% forgetting the Romans had conquered Britain.
The 1,000-person poll marks the start of BBC2's Battlefield Britain series.
A third of 16 to 34-year-olds did not know that William the Conqueror won the Battle of Hastings, while more than a fifth of 16 to 24-year-olds thought Britain had been conquered by the Germans, the Americans or the Spanish.
On average, only half of all age groups knew it was the Battle of the Boyne, in which Catholic King James II's troops were defeated by Protestant William III in 1690, that is celebrated by the Orangemen on 12 July in Northern Ireland.
While 71% of over-65s got that question right, only 18% of 16 to 24-year-olds did.
And despite hefty media coverage of the 60th anniversary of the D-Day landings - a decisive World War II battle - almost a third of all age groups were unable to say the Battle of Britain happened during that war.
Nick Seaton, chairman of the Campaign for Real Education, said the poll "clearly shows that our state education system has got a lot to answer for".
He added: "This is extremely shocking."
Battlefield Britain presenter Peter Snow called the findings "a shock and a challenge".
He said: "Battlefield Britain can put this right by giving viewers some of the most striking and vivid images yet seen of the violent events that shaped our history."
The series starts on BBC2 at 2100 BST on Friday.