In 1819 he left for Rome and moved to the Roman countryside, where he frequented the prestigious artistic environment gathered around Villa Cybo; he met the Flemish painter Verstappen, whose studio he attended as a pupil in Rome.

In 1820 he exhibited some works at the University Palace of Turin and in 1826 he ended his stays in the Roman countryside. During a trip to Naples in 1827 he met Anton Sminck van Pitloo; D'Azeglio's notebooks from that period are full of sketches of the Neapolitan city and Sorrento.

Having returned to Turin, between 1819 and 1820, he dedicated himself to one of his most famous historical paintings: The Challenge of Barletta and to the novel Ettore Fieramosca published in 1833.

In 1831 he moved to Milan, where he met and began to frequent Alessandro Manzoni assiduously; Not much time had passed since then when D'Azeglio's wedding was celebrated with the poet's daughter, Giulia, who made him the father of a little girl.

D'Azeglio became a successful painter and until 1843 his landscape paintings, with historical, literary and chivalric subjects, were well displayed in various artistic events. From the second half of the 1840s, he embarked on a political career, accepting the direction of the liberal movement in Romagna. In 1845 he obtained an audience with Carlo Alberto and on that occasion the king pronounced the famous phrase: "Let those gentlemen know that they remain quiet and do not move, as there is nothing to do for now; but let them be certain that if the opportunity presents itself, my life, the lives of my children, my weapons, my treasures, my army, everything, will be spent for the Italian cause".