100 years ago, on 4 August 1914, the British Empire declared war on Germany, and thus became embroiled in the largest and deadliest conflict at that point in human history.

Due to technological advances with filming equipment during the turn of the century, the Great War, as it was referred to at the time, was also the first global conflict to be captured on film cameras. 

In the incredible archive footage here, the horrors of the trenches to the innovations in military technology, the deadly conflict in which more than 9 million combatants were killed, is vividly brought to life.