An archive picture shows a priest celebrating Mass for French soldiers on the Champagne front in eastern France in 1915. A viscount in the Armored Cavalry Branch of the French army left behind a collection of hundreds of glass plates taken during World War I that have never before been published. The images, by an unknown photographer, show the daily life of soldiers in the trenches, destruction of towns and military leaders. The year 2014 marks the 100th anniversary of the start of WWI. (CNS photo/courtesy of the Collection Odette Carrez via Reuters)