Fire, plunderers and army camps
On the Tuesday after Easter 1423 a great fire broke out in Diegem, and some took advantage of the confusion to steal. In 1537 Emperor Charles V granted the inhabitants a reduction of war contributions because of the damage done by mercenary bands. In 1542 the Guelders warlord Maarten van Rossem plundered his way through Brabant; for years afterwards Diegem still had ‘plots where a house used to stand’. In the second half of the 17th century armies repeatedly camped on the Diegem plateau, tens of thousands of soldiers at a time; in 1690 the Prince of Saxony simply turned a miller, his wife and eight children out of their house.
In September 1830, 5,000 to 6,000 Dutch soldiers under the Prince of Orange camped in the Woluwe valley before advancing on Brussels. On 21 September a few people from Brussels and volunteers from Liège fought the Dutch cavalry not far from Evere, and on 27 September the defeated army withdrew through Diegem. The requisitions cost Diegem 4,193.91 francs. Afterwards there was little money for celebrations: in 1837 the September festivities did not take place and the inhabitants preferred to go to Brussels.
The First World War
In 1914-1918 everything revolved around food. In March 1916 the municipality introduced a potato card: children received 200 grams a day, those over seven 300 grams. Diegem joined a cooperative of municipal stores, and the municipality opened a store in the house of Jan Vanhooff. After the war the municipality erected the memorial to the fallen, and in 1930 a great procession went through the village for Belgium's centenary.
The Second World War
On 15 May 1940 a British officer came to report that the Germans had crossed the Dyle; heavy guns were already in position and the village had to be evacuated by midnight. On the evening of 17 May German troops occupied Diegem, and by 18 May the services were working again. After sabotage and shots at a German sentry on the night of 23 to 24 July 1940, the Germans took three inhabitants hostage. On 5 September 1944 the municipal authorities announced on a poster that they were back in charge, and called on people to prevent looting and violence.
Fallen for Belgium
Sixteen men from Diegem fell in the two world wars: Frans Buekenhout, Ferdinand Campine, Victor De Ceuster, Lodewijk De Greef, Filip De Kleermaeker, Adolf Denon, Jan Baptist Dils, Jan Baptist Elaerts, Jan Baptist Jacobs, Jan Baptist Paulus, Camiel Vandensteen, Frans Vanhout, Lodewijk Van Keerberghen and Guillaume Willox in 1914-1918, and Gustaaf Michiels and Anthruan Vanderveken in 1940. Many of their names live on as street names. After the war Eugène Blairon, who died in a German concentration camp, and Frans Gurickx, shot by the Gestapo in Nossegem, were also given streets.