Hans Eleonardus Møller Sr. started his career working for his father-in-law Nicolai Benjamin Aall. Following the death of N. B. Aall in 1798, Møller continued working for inheritor Niels Aall. From 1811 they co-owned a company Aall &amp; Møller, but this was not profitable and was dissolved. Møller had invested 100,000 rigsdaler in the venture. He instead started as a merchant of his own, having acquired burghership in October 1803. Concentrating on timber merchantry, he also owned several ships. The Gunboat War from 1807 to 1813 saw the loss of many ships, but he invested and had the ships replaced. One ship seized in 1812 was bought back in 1814. He bought his last ship in 1828. Jacob Aall, father-in-law of two of Møller's children, described Møller as "one of Norway's most active and skillful merchants".