Members of the military and volunteers lit the torches, during a ceremony that featured special music, by composer Mira Calix, punctuated by words from Sonnets to a Soldier, a collection of poems by American poet Mary Borden, who also served as a nurse for the French Red Cross during the war.

The ceremony also featured a minute of silence for the dead or injured. Nearly 900,000 British and Colonial soldiers died during the war. More than 1.6 million were injured.

The four-year conflict, then called the Great War, ended officially on November 11, 1918. Ceremonies are planned in many places around the world on the centenary of that day. The Tower of London torches ceremony will be repeated every night, through Nov. 11, Armistice Day.