He learnt at the Academy in Vienna for two years. He took part in the war of independence of 1848-49 as a major. From then, he lived in Italy and Békéscsaba, in the end he settled down on the island of Capri, where he built a most friendly tusculanum. Haan painted pictures on religious subject matters, and altar pieces. Ordered by the Hungarian National Museum, he copied Raphael's stanza frescoes in their original size. Major pictures: "Portrait of Pope Pius, IX", 1857, "Leda with Swan", 1861 and "Man Reading Newspaper". Together with Lajos, his brother, a pastor, he published an allegorical chronology to the history of the Hungarian Protestant church. It was so favourably accepted that it was published once more in two weeks.