From his start as a cadet in 1706 Knud Benstrup was on active service throughout the Great Northern War, in 1715 as a junior lieutenant in the ships-of-the-line Justitia and then Ditmarsken under Admiral Christian Thomesen Sehested in the Pommeranian campaigns.
From here, he was ordered home and sent, in the spring of 1714, to France where he would study the theory and mathematics of ship design and the practice of shipbuilding at Brest which at that time was a centre of excellence.
Benstrup was ordered by Admiral M Bille to strip out excess timber without altering the integrity of the hull but in doing so he departed from the design plans that had had royal approval.
The commission[Note 1] decided by a majority and gave Benstrup a severe sentence - execution was suggested by Krag - which Lütken and Lützow took heavy objection to.
Benstrup himself got the opportunity later to present his defence against the accusations but did so without legal representation and in such a fierce and disrespectful manner that he was forced to face a court martial which deemed he had broken his terms of office and sentenced him to imprisonment in Kastellet, the military citadel and prison.
Forbidden to leave Denmark and banished from Copenhagen, but in possession of a pension, Benstrup chose to return to his home town of Ebeltoft where he lived until his death on 26 February 1742.