More than four in 10 Britons do not know which conflict the Battle of the Somme took place in, according to new research ahead of the 100th anniversary of the calamitous First World War offensive.
Some 43% of people did not know the battle, the bloodiest in the British Army's history, occurred during the 1914-1918 war, according to a survey by the National Army Museum.
Almost half (46%) were unaware it took place in 1916 or that the artillery-scarred battlefield was in France.
And the group that expressed the least knowledge about the battle was the "baby boomer" generation, with 88% of those aged 55 to 64 saying they knew little or nothing about it.
Tristan Langlois, head of learning at the National Army Museum (NAM), said: "This year marks the centenary of the Battle of the Somme, arguably one of the most significant battles of the First World War, and it's important that the sacrifices that were made both in battle and at home aren't forgotten."
The NAM polled more than 2,000 people as it launched its Somme "centenary learning package" at www.nam.ac.uk, which includes maps, videos and soldiers stories through items including diary entries and photographs.
The Somme was a battle that claimed almost 20,000 British lives on the first day alone. There were more than a million casualties on both sides by the time it ended after 141 days on November 18 1916.
It is hoped people will hold vigils at sundown on June 30 or on July 1, gathering at appropriate places or in their own homes, lighting candles, reading poems or listening to music and sharing photographs of relatives who fought in the battle.
The centenary is being marked with a series of formal events including a national commemoration in Manchester and vigils at Westminster Abbey in London, Edinburgh, Cardiff and County Down, Northern Ireland.
There will also be an international commemorative event on July 1 at Thiepval, in northern France, where a memorial stands to more than 72,000 men who died on the Somme and have no known grave.
Beginning on July 1 1916 and intended to achieve a decisive victory for the British and French, the Somme became a bloody stalemate on battlegrounds that turned into a muddy quagmire after torrential rains in October of that year.