In 1907 Kessler graduated from the
Technische Hogeschool Delft (
Delft University of Technology), as a mechanical engineer. He worked for the company until 1915, when he left to look for a different job. As Joost Jonker and Jan Luiten van Zanden write in
A History of the Royal Dutch Shell, his fiancée, Elizabeth "Bep" Stoop (herself a daughter of a prominent oil explorer,
Adriaan Stoop), "put his love for her to the test by asking him to choose between her and the Group." His younger brother
Jean Baptiste August "Guus" Kessler Jr., who had married Bep's cousin, Anna Francoise "Ans" Stoop, continued with the Royal Dutch and eventually rose to head their father's company. In 1918 Dolf joined the committee for the funding of the
Hoogovens (
Dutch Blast Furnaces). "His drive, entrepreneurship, imagination and leadership secured Hoogovens a firm foothold in a very competitive industry at a very difficult time." Kessler would remain the director of Hoogovens until his death from a brain tumor in 1945, with a short break during the
Second World War, when the Germans kept him hostage in camp
Kamp Sint-Michielsgestel. ==Personal life==