After graduating from Rønne Realskole at 17 years of age, Zahrtmann was sent to Sorø Academy, where he studied painting with landscape painter Hans Harder.

[3] After graduating, Zahrtmann came to Copenhagen, where during the winter of 1863–1864 he studied drawing at the Technical Institute under Christian Hetsch and architect Ferdinand Vilhelm Jensen.

Zahrtmann had already become interested in the story of the heroic 17th century daughter of a Danish king, Leonora Christina Ulfeldt (also known as Eleanor Christine), before the 1869 posthumous publication of her 1674 autobiographical narrative Jammers Minde ("Remembrance of Misery"), which he received as a birthday gift from Haslund and Krohn.

Countess Leonora Christina of Schleswig-Holstein, King Christian IV's daughter by his morganatic love marriage to a noble Danish maiden, had fallen from grace because of her husband Corfits Ulfeldt's high treason.

The first of these paintings was made public in 1871, Slotsfogden skjæmter med Kvinderne i den nylig fængslede Kongedatters Kammer paa Blaataarn ("Castle Keeper Banters with Women in the Chamber of the King's Daughter in the Blue Tower").

In 1873 he won another Neuhausen Prize for Sigbrit gennemgår toldregnskaberne med Christian II ("Sigbrit Reviews Tax Accounts with Christian II"), and exhibited a preparatory painting for Job og hans Venner ("Job and His Friends"), which won him the Academy's gold medallion.

In 1873 he also painted "Scene from the Court of Christian VII 1772" to retell the tragic story of Queen Caroline Matilda on the centennial of the fall of Johann Friedrich Struensee.

Zahrtmann tried to extract a travel stipend from the Academy three times, which should have been due him as winner of the large gold medal, but the funds were not forthcoming until two years later.

Zahrtmann spent the summer of 1873 at Hornbæk (Helsingør municipality) in the company of fellow painters Peder Severin Krøyer and Viggo Johansen.

He later returned to Italy many times, including in 1882–1884 on an Ancher Fund grant along with artists Joakim Skovgaard, Theodor Esbern Philipsen, and Viggo Pedersen.

He was fascinated by everyday life there, by the strong Italian sun, the vivid colors, and the exotic splendor of Roman Catholic Church rites which he depicted in many paintings.

Between 1890 and 1911 he spent every summer in Civita d'Antino, living with the Cerroni family and gathering friends and students in an annual artist colony.

Late in life, Zahrtmann produced a number of paintings of nude men, including Prometheus (1906), Sokrates og Alkibiades (1907, 1911), and Adam i Paradis (in two versions, 1913–14).

In an era that was still shaken by the Great Scandinavian Sexual Morality Debate of the outgoing 19th century, these works were immediately scored as scandalous violations of public decency.

The relief was drawn by architect Thorvald Bindesbøll and painter Joakim Skovgaard, and was carved from Bornholm granite by Larsen Stevns.