The young artist left Lubeck in March 1806, and entered as student the academy of Vienna, then under the direction of Heinrich Füger, a painter of some renown, but of the neoclassical school of the French Jacques-Louis David. Here was gained thorough knowledge, but the teachings and associations proved unendurable to the sensitive, spiritual-minded youth. Overbeck wrote to a friend that he had fallen among a vulgar set, that every noble thought was suppressed within the academy and that losing all faith in humanity he turned inwardly on himself. These words are a key to his future position and art. It seemed to him that in Vienna, and indeed throughout Europe, the pure springs of Christian art had been for centuries diverted and corrupted, and so he sought out afresh the living source, and, casting on one side his contemporaries, took for his guides the early and pre-Raphael painters of Italy. At the end of four years, differences had grown so irreconcilable that Overbeck and his band of followers were expelled from the academy. True art, he writes, he had sought in Vienna in vain:
Oh! I was full of it; my whole fancy was possessed by Madonnas and Christs, but nowhere could I find response.
Accordingly he left for Rome, carrying his half-finished canvas "Christ's Entry into Jerusalem", as the charter of his creed "I will abide by the Bible; I elect it as my standing-point."
Overbeck in 1810 entered Rome, which became for 59 years the centre of his labor. He was joined by a goodly company, including Peter von Cornelius, Friedrich Wilhelm Schadow and Philipp Veit, who took up their abode in the old Franciscan convent of San Isidoro and became known among friends and enemies by the descriptive epithet the Nazarenes, the German-Roman artists, the church-romantic painters, the German patriotic and religious painters. Their precept was hard and honest work and holy living; they eschewed the antique as pagan, the Renaissance as false, and built up a severe revival on simple nature and on the serious art of Perugino, Pinturicchio, Francia and the young Raphael. The characteristics of the style thus educed were nobility of idea, precision and even hardness of outline, scholastic composition, with the addition of light, shade and colour, not for allurement, but chiefly for perspicuity and completion of motive. Overbeck was mentor in the movement; a fellow-labourer writes: No one who saw him or heard him speak could question his purity of motive, his deep insight and abounding knowledge; he is a treasury of art and poetry, and a saintly man. But the struggle was hard and poverty its reward. Helpful friends, however, came in Niebuhr, Bunsen and Frederick Schlegel. Overbeck in 1813 joined the Roman Catholic Church, and thereby he believed that his art received Christian baptism.
Timely commissions followed. The Prussian consul, Jakob Salomon Bartholdy (1779-1825, uncle of Felix Mendelssohn), had a house on the brow of the Pincian, called Palazzo Zuccari or Casa Bartholdy, and he engaged Overbeck, Peter von Cornelius, Philipp Veit and Friedrich Wilhelm Schadow to decorate a room 7 m square with frescoes (now in the Alte Nationalgalerie, Berlin) from the story of Joseph and his Brethren. The subjects which fell to the lot of Overbeck were the Seven Years of Famine and Joseph sold by his Brethren. These tentative wall-pictures, finished in 1818, produced so favourable an impression among the Italians that in the same year Prince Massimo commissioned Overbeck, Cornelius, Veit and Schnorr to cover the walls and ceilings of his garden pavilion, near St. John Lateran, with frescoes illustrative of Tasso, Dante and Ariosto. To Overbeck was assigned, in a room 5 m square, the illustration of Tasso's Jerusalem Delivered; and of eleven compositions the largest and most noteworthy, occupying one entire wall, is the Meeting of Godfrey de Bouillon and Peter the Hermit. After ten years delay, the overtaxed and enfeebled painter delegated the completion of the frescoes to his friend Joseph von Führich. The leisure thus gained was devoted to a thoroughly congenial theme, the Vision of St Francis, a wall-painting 6.5 m long, figures life size, finished in 1830, for the Porziuncola in the Basilica of Santa Maria degli Angeli near Assisi.
Overbeck and the brethren set themselves the task of recovering the neglected art of fresco and of monumental painting; they adopted the old methods, and their success led to memorable revivals throughout Europe.
Fifty years of the artist's laborious life were given to oil and easel paintings, including:
All the artist's works are marked by religious fervour, careful and protracted study, with a dry, severe handling, and an abstemious colour.
Overbeck belongs to eclectic schools, and yet was creative; he ranks among thinkers, and his pen was hardly less busy than his pencil. He was a minor poet, an essayist and a voluminous letter-writer. His style is wordy and tedious; like his art it is borne down with emotion and possessed by a somewhat morbid subjectivity. His pictures were didactic, and used as means of propaganda for his artistic and religious faith, and the teachings of such compositions as the Triumph of Religion and the Sacraments he enforced by rapturous literary effusions. His art was the issue of his life: his constant thoughts, cherished in solitude and chastened by prayer, he transposed into pictorial forms, and thus were evolved countless and much-prized drawings and cartoons, of which the most considerable are the Gospels, forty cartoons (1852); Via Crucis, fourteen water-color drawings (1857); the Seven Sacraments, seven cartoons (1861). Overbeck's compositions, with few exceptions, are engraved. His life-work he sums up in the words "Art to me is as the harp of David, whereupon I would desire that psalms should at all times be sounded to the praise of the Lord."
He died in Rome in 1869. He was interred in the church of San Bernardo alle Terme