[1] He was a relative of several other high officers in the army and navy of the Dutch Republic and Kingdom of the Netherlands, among whom Willem Frederik van Bylandt, who commanded a brigade at the Battle of Waterloo.
This expedition was successful in its object to force Sultan Mohammed ben Abdallah to sue for peace, and give the Dutch victory in the Dutch-Moroccan War (1775-1777).
Dutch and French merchants imported guns and munitions, and also naval stores to St. Eustatius, which were then re-exported to the rebellious American colonies.
This treaty guaranteed Dutch shipping a privileged status and exempted it from trade embargoes enforced by the British Royal Navy as far as non-contraband goods were concerned.
The British tried to declare naval stores, like ship's timbers, spars, masts, rope, tar and pitch, contraband, against which the Dutch maintained the narrow definition of the treaty as only "arms and munitions."
[6] After the Affair the relations between the Republic and Great Britain steadily deteriorated, and the latter started the Fourth Anglo-Dutch War in December 1780.
The Dutch colonies in the West Indies were immediately attacked and Great Britain soon captured St. Eustatius that was subsequently sacked by Admiral George Rodney.
According to his biographer Molhuysen Van Bylandt was also sent to the area and he successfully organized the defense of Curaçao, which remained in Dutch hands.
[7] However, other sources, notably Dirks, tell us that Bylandt was never directly involved in the defense of Curaçao, but only detached a ship of the squadron with which he was staying in Lisbon at the time for that purpose.
After long dithering the Dutch decided to provide ten ships of the line for such a project, and Van Bylandt was put in charge of this squadron.
[11] During his career he made great contributions to codification of naval tactics with his Zeetactiek of Grondregelen der krijgskunde ter zee ("Naval tactics or Fundamentals of military science at sea;" Amsterdam, 1767) and he is also credited with restoring discipline in the fleet, which apparently had reached a low level at some point.