[1] Arnold Jan d'Ailly was born in Franeker and grew up in Doesburg, Gelderland as the son of a general practitioner.

[2] After 1944, he assisted in financing the 1944 railway strike that intended to break down German logistics during operation Market garden.

[2] Arnold Jan d'Ailly had never publicly shown an interest in politics, until he joined the recently founded Labour Party in 1946.

He spearheaded infrastructure projects such as the completion of the Amsterdam–Rhine Canal, the Utrechtseweg highway,[3] the expansion of the Amsterdam docks, and the recovery of Schiphol international airport.

[2] Between 1952 and 1956, Arnold Jan d'Ailly's was also the head of the Council of Municipalities (Vereniging der Nederlandse Gemeenten, VNG).

In 1949, in response to the Czechoslovak coup d'état one year earlier, Arnold Jan d'Ailly fired aldermen Ben Polak and Leen Seegers of the Communist Party on the Amsterdam council, a move that was on uneven footing with municipal law at the time.

[1] d'Ailly was equally on good terms with the Dutch royal family, and took part in the commission that assisted Princess Beatrix in her ascendency to queen.