Diegem was a sub-mayoralty of Vilvoorde in the Duchy of Brabant. The lord appointed a mayor and aldermen; in 1650-1660 Jan vander Perre was mayor, and in the 18th century the Steenokkerzeel notary Joannes Judocus van Frachen was bailiff. Under French rule Diegem became a municipality of the Dyle department, with mayors such as Henri Joseph vanden Plas, the notary Pierre Jacques van Gansen and the innkeeper Jean de Roover. After 1830 Diegem belonged to the canton of Sint-Stevens-Woluwe, from 1867 to Sint-Joost-ten-Node and from 1904 to Schaerbeek. In 1853 the council still rejected any merger with Brussels. On 25 September 1963 Diegem was twinned with Northbrook, Illinois, and on 1 January 1977 it merged with Machelen.
The mayors
After Carolus de Baudignies (until 1832) came Pieter Mattheussens, Judocus Jacops (from 1840) and Frans Ferdinand Tenaerts, mayor from 1850 until his death in 1883. Then came Doctor Eugène Van der Aa (1883-1906), Georges De Coninck of the cardboard works (1906-1921), the miller Frans De Kelver (1921-1938) and Alfons De Cock (1938-1950). During the war first alderman Corneel De Ceuster replaced him at first, and from December 1941 Jozef Teugels was wartime mayor. After De Cock came Jan Emiel Mommaerts (1951-1967), the schoolteacher Gaston Blairon (1967-1976) and finally Hendrik Campine, the last mayor of independent Diegem in 1976. Many of them gave their name to a street or square.
Language, finances and police
Until the mid-19th century the municipal authorities wrote everything in French; from 1855 Dutch-language minutes appear now and then, and in 1907 the council demanded specifications in Dutch. In 1922 the council called for Ghent University to teach in Dutch. Finances were long tight: in 1826 the municipality could not afford a fire pump and cancelled its subscription to Le Journal de Bruxelles. A notable source of income was the pitch fee at the Easter fair, recently around 100,000 francs. In 1922 there was even a tax on wedding processions: 10 francs per carriage, 20 per car.
The first known rural policeman is Laureys Vanderpoorten (1804). One of his successors, Carolus Vanvarenbergh, was reprimanded in 1844 for drunkenness, speaking ill of the municipal authorities and keeping company with poachers until midnight; a few months later it was said that he was ‘mending his ways’. In 1826 the pubs had to close at 9 p.m. in winter and at 10 p.m. the rest of the year; the church bell announced closing time. In 1957 a Civil Defence corps was founded, which at once had 88 members.