On 2 August 1914, Germany presented Belgium with an ultimatum: the free passage of Reich troops headed towards France, or the invasion of its territory. The Belgian government had twelve hours to reply. After consultation, King Albert refused to give in to the ultimatum, in the name of the obligatory neutrality of the country. Two days later, on 4 August, the German troops crossed the national border. Belgium was at war! As soon as the news spread, the people of the capital took to the streets. The city was adorned with national flags, while the people sang the Brabançonne.
From Laeken Palace to Brussels Park, the multitude gathered on the sidewalks to acclaim their sovereign heading toward the assembled Chambers. “Never, since 1830, has there been such a critical moment for Belgium: The integrity of our territory is threatened”. The country will resist in the name of justice and of honour, pursued the sovereign, hailed at length by the parliamentarians of all sides. Indignation was palpable: was the German invader not one of the guarantors of Belgian neutrality since the Treaty of London in 1831? A “sacred union” formed around the defence of the endangered fatherland. Even the groups which opposed the legitimacy of the Belgian nation state—namely the more radical fringes of the Flemish and socialist movements—rallied to this new common cause.