The history of Brussels Airport start in World War I when the German troops build an airship hangar on a plain on the territory of Haren and Evere. After the armistice of 11 November 1918 the Belgian military started to use the airfield and the remaining infrastructure. The zeppelin hangar that was not pulled down until 1923 was used to park the aircraft the Germans had left behind. A few of these aircraft would later be used to take civilians up on their first flight from Haren.
From the earliest days the Belgian royal house took a keen interest in aviation. On 31 March 1919 King Albert I signed the memorandum of association of SNETA (Syndicat National pour l'Etude des Transports Aériens). A week after its creation, SNETA set up a test flight that would carry two passengers from Brussels to London, and back to Evere via Paris in a former German bomber. The whole flight took seven and a half hours, the time we need today to fly from Brussels to New York.
Little by little scheduled services were organised between Brussels and the British and French capitals. The military tolerated the civil aviation activities on its airfield. The military part of the airfield was referred to as Evere, whereas all civil activities took place on the territory of Haren. The first passengers that left from Haren were received in a small wooden building along the Haachtsesteenweg. Next to the wooden building a first brick Aérogare was constructed that served mainly to accommodate the administrative services.
The only large wooden hangar for civil aircraft burnt down on 27 September 1921. Because part of the SNETA fleet also went up in flames a large number of scheduled flights had to be cancelled. Soon after, the construction of brick hangars began. These hangars were enormous so that the still rather frail aircraft could be parked indoors in winter. In August 1923 the first radio transmission station became operational.
In December of the same year SNETA successor Sabena got permission to build a new airport terminal. On 12 February 1925 the Sabena Handley Page W8f O-BAHO "Princesse Marie-José" took off near the hangars on its first Congo flight.
A week after Charles Lindbergh had flown his "Spirit of St.-Louis" from New York to Paris, he landed at Haren. The hero was received in Brussels by King Albert I and Queen Elisabeth.
Aviation continued to grow steadily and on 29 September 1929 the new airport terminal was taken into use. Although Haren still had a grass landing strip, a concrete apron was laid in front of the terminal so the passengers no longer had to walk through the dirt and mud to board their plane.
In the early years of its existence, our civil airport didn't have an actual runway. Planes simply took off against the wind from the large grass field. In the middle of the field a white circle was drawn with a large arrow pointing north. A smoke pot indicated the wind direction. Even gliders were still allowed to land at Haren in the thirties.
Sabena was not the only airline at our airport. By the middle of the 1930s several foreign airline companies operated from our national airport: Imperial Airways, Air France, KLM, Deutsche Lufthansa, Hillman's Airways (to London with a stop at Het Zoute) and British Continental Airways. Also in those days pooling and close collaboration between airlines were common practice. With the number of movements amounting to 45,000 a year (compared to 237,888 in 2017), voices rose to modernize and expand the airfield at Haren.
On 23 February 1935 Haren saw the start of the first scheduled service to Congo, 10 years after the legendary trip of pioneer Thieffry and his crew. The complete modernization of the infrastructure of Haren would never come to be. On 10 May 1940 the German troops invaded Belgium and within the week occupied the aerodrome.