He started his career in the administration of the Gold Coast as a substitute judge at the Court of Justice in Elmina and was promoted to commandant of Fort Lijdzaamheid at Apam on 3 January 1859.
In January 1867, he left the outer forts for Elmina Castle, where he became registrar of the civil registry, director of the newly established post office, and notary.
In May 1868, just after the Convention for an Interchange of Territory on the Gold Coast between the United Kingdom and the Netherlands had been put into effect, Le Jeune went on European leave again, and returned in February 1869.
[4][5][6] Le Jeune, who by now was a well-experienced administrator, immediately took up the position of bookkeeper, officer of justice, secretary, cashier, and bailiff, making him second-in-command of the colony.
Nagtglas immediately tried to subdue the people around Fort Komenda, who had resisted Dutch rule, but only managed to escalate the situation, culminating in the hostage of several able seamen from the warship Amstel a few days later.
Hugenholtz had appointed the naval officer Johannes Wirix as his successor, much to the dismay of the veterans of the colonial administration, who felt passed by.
[12] The couple settled in Neerbosch [nl], now part of Nijmegen, where they had two sons and a daughter, before moving to the Brussels municipality of Schaerbeek in March 1879.
[13] The year after, on 2 September 1895, his daughter died as well, prompting his widow Maria Luther to move back to her maiden family in Rotterdam in March 1896.