[4] Although Dahl spent much of his life outside of Norway, his love for his country is clear in the motifs he chose for his paintings and in his extraordinary efforts on behalf of Norwegian culture generally.

Still, Dahl looked back on his teacher as having kept him in ignorance in order to exploit him, putting him to work painting theatrical sets, portraits, and views of Bergen and its surroundings.

Dahl held that a landscape painting should not just depict a specific view, but should also say something about the land's nature and character – the greatness of its past and the life and work of its current inhabitants.

As one critic has put it, "Unlike the radically Romantic works also appearing at the time, Dahl softens his landscape, introducing elements of genre painting by imbuing it with anecdotal materials: In the background a wisp of smoke rises from a cabin, perhaps the home of the hunter on the snow-covered field."

In accordance with this reigning taste, Dahl attempted to give his Danish themes a certain atmospheric character in order to lift them up above what was considered a merely commercial level.

But at the same time it was his deepest wish to provide a more faithful picture of Norwegian nature than were offered by the old-fashioned, dry paintings of Haas and Lorentzen.

He arrived with introductions to the city's leading citizens and to major artists such as Caspar David Friedrich, who helped him establish himself there and became his close friend.

[3] One critic has written: "Friedrich's still, meticulously executed landscapes - products of an art informed by his strict Protestant upbringing and a seeking for the divine in nature - were justifiably famous by the time he and Dahl became acquainted.

'"[6] Together with Friedrich and Carl Gustav Carus, Dahl would become one of the Dresden painters of the period who exerted a decisive influence on German Romantic painting.

Another monumental waterfall painting, completed the next year, was lavished with praised by the critic for Kunstblatt who said that Dahl was greater than Jacob van Ruisdael.

In 1823 Dahl moved in with Friedrich, so that many of his students, such as Knud Baade, Peder Balke, and Thomas Fearnley, were equally influenced by both artists.

"Well before their meeting," writes one critic, "Dahl had also painted a number of 'moonlights' and, travelling in Europe, he was in the Bay of Naples in 1821 when Mount Vesuvius was active.

Here he painted 'Boats on the Beach Near Naples', where fishing crafts lie at anchor in the calm, shimmering waters with the twin peaks of the mountain smoking and flaming behind.

Predictably, after his close association with Friedrich began—the two families shared a house in Dresden from 1823—he was considerably influenced by him, but his own more spontaneous and painterly style soon prevailed.

It was this impulse toward individuality that later caused him to turn down an offer of a permanent chair at the academy – he didn't want to feel compelled to show up for class when he was busy working on a painting.

Like John Constable, Dahl felt that the sky was an important part of a landscape painting, and he never grew tired of watching the clouds move over the flat plain.

Whereas in Friedrich's work a woman dressed for the windy weather sits idly watching five fishing boats sailing past, in Dahl's picture, there seems to be a more personal note, with echoes of his own upbringing in a seafaring community, as the mother and small child eagerly await the return of the little ship from the sea.

This small picture, measuring only 18.5 x 34.5 cm (7¼" x 13½"), shows the dome of the Frauenkirche and the tower of the Hofkirche dominating the skyline; silvers and deep blue combine to give it a wonderful jewel-like effect, together with a certain elegiac quality, perhaps indicative of the artist's awareness that his long friendship with Friedrich was nearing an end.

Some years later this youngest child also died, leaving Dahl with two surviving children, Siegwald and Caroline, who married the Norwegian minister Anders Sandøe Ørsted Bull 1848.

In 1902, a statue of Dahl by Norwegian sculptor Ambrosia Tønnesen (1859–1948) was erected on the facade of the West Norway Museum of Decorative Art in Bergen.