It was a four year conflict which claimed more than 16 million lives, including nearly a million Britons.
The centenary of the First World War falls in two years time and the Prime Minister called for a national commemoration to mark the sheer scale of sacrifice.
David Cameron said there would be events to mark 100 years since the outbreak of war in 2014, Armistice Day in 2018, and the dates of major battles in between.
He said: "Our ambition is a truly national commemoration worthy of this historic centenary. A commemoration that captures our national spirit in every corner of the country, from our schools and workplaces, to our town halls and local communities.
"A commemoration that, like the Diamond Jubilee celebrations this year, says something about who are as a people. Remembrance must be the hallmark of our commemorations."
Some £50m was being spent on the commemorations in total.
The commemorations will include the centenary of the first day of conflict on August 4, 2014, the start of the Battle of the Somme on July 1, 2016, and further events to mark Jutland, Gallipoli, Passchendaele and Armistice Day in 201
Neil Griffiths of the Royal British Legion Scotland discussed the issue with Scotland Tonight, along with historical consultant Des Brogan who has taken thousands of school students and adults on tours of World War One battlefields.
More About Scotland Tonight
- David Cameron hails the Union as 'greatest merger in history'
- Douglas Alexander says referendum debates has 'divided' Scotland
- Scotland Tonight: Will family politics decide the referendum?
- More than 120 business people back Scotland to stay as part of UK
- Salmond renews call for Cameron debate after victory over Darling
- First Minister and Alistair Darling clash in fiery second TV debate
- Holyrood recess begins as referendum campaigns go into top gear