Schmettow belonged to German nobility. He grew up in Denmark, where he had a military upbringing. As a teenager he took part in the European Seven Years war on the Prussian side. In 1774 he was promoted to colonel, and in 1776 he was appointed head of the 3. Trondhjemske Infanteriregiment [Third Infantry Regiment from Trondheim]. He was awarded the rank of major general in 1787, and rose further to lieutenant general in 1802. Schmettow attached great importance to schooling his officers, and it is claimed that he is a pioneer in this field. In 1814 his military career peaked when he was appointed commanding general for "det nordenfjeldske" [the northern half of Norway]. But he did not remain in this position for long.
Norway had been ceded to Sweden at the Treaty of Kiel in January 1814. During the political negotiations that same year Schmettow, who spoke several languages, was allowed into the circle around Prince Christian Frederik, who was working very hard to make Norway independent. Schmettow participated actively in the negotiations with the Swedes as the year was passing, earning the wrath of the Swedes for his unyielding attitudes and harsh words. In the end the general was simply sacked. However, this was not as dramatic as it might have been as Schmettow had reached a relatively advanced age.
In civilian life Schmettow married Christiane Møllmann in 1778, thus becoming quite well off. He came to own Rotvoll, in addition to Mostadmarken ironworks and several large properties in town. At Rotvoll the couple hosted large social events and the remains of his wine cellar can still be seen in the terrain. Even more prominent in the landscape is Schmettow's avenue, which runs south in the direction of Brundalen. The general was an eager farmer, and carried out many experiments with fruit and vegetable growing. He was also a very well-read man, leaving behind a large collection of books. As an individual it is not unreasonable to call him colourful. He was helpful and hospitable, but also moody, vain and easily annoyed.
In accordance with his wishes he was given "a simple soldier's funeral" when buried in the Cathedral cemetery in 1821. He was survived by two daughters.
Recommended reading: Strinda den gang da [Strinda once upon a time]. Year book by Strinda history association 2013 (Articles by Jan P. Breida).