On July 24, 1914, the Belgian government had announced that if war came to Europe, it would uphold its neutrality. The neutrality of Belgium had been guaranteed by the Treaty of London (1839), which had been signed by Prussia. However, the German Schlieffen Plan required that German armed forces violate Belgium’s neutrality in order to outflank the French Army, concentrated in eastern France. The German Chancellor dismissed the treaty of 1839 as a “scrap of paper.” The Belgian government mobilized its armed forces on July 31 and a state of Kriegsgefahr (“danger of war”) was proclaimed in Germany. On August 1, the German government sent an ultimatum to Belgium, demanding passage through the country. Two days later, the Belgian Government refused Germany’s demands and the British Government guaranteed military support to Belgium. The German government declared war on Belgium on August 4, 1914 and troops crossed the border and attacked.
The German army immediately began to engage in numerous atrocities against the civilian population of Belgium, and destruction of civilian property. Thousands of Belgians were killed, homes destroyed and in many cases entire communities destroyed. One and a half million Belgians (20% of the entire population) fled from the invading German army.
Désiré Mercier was born at the château du Castegier in Braine-l’Alleud, as the fifth of the seven children. Mercier received the clerical tonsure in 1871, and was finally ordained to the priesthood by Archbishop Giacomo Cattani, the nuncio to Belgium, in April 1874. He obtained his licentiate in theology (1877) and doctorate in philosophy from the University of Louvain, and also took courses in psychology in Paris. Three of Mercier’s sisters became nuns. Mercier was created Cardinal by Pope St. Pius X in April 1907.
During the German atrocities of 1914, thirteen of the priests in Mercier’s diocese were killed, not to mention the many civilians. In response Mercier wrote a pastoral letter, Patriotism and Endurance.
“If any man had rescued you from shipwreck or from a fire, you would assuredly hold yourselves bound to him by a debt of everlasting thankfulness. But it is not one man, it is two hundred and fifty thousand men who fought, who suffered, who fell for you so that you might be free, so that Belgium might keep her independence, her dynasty, her patriotic unity; so that, after the vicissitudes of battle, she might rise nobler, purer, more erect, and more glorious than before.”
The pastoral letter had to be distributed by hand as the Germans had cut off the postal service. His passionate, unflinching words were taken to heart by the suffering Belgians.
On January 3, 1915 Cardinal Mercier was placed under house arrest by German military authorities. The reading of his pastoral letter has been banned.