Deriving from his work as an artist, the passion for collecting and dealing developed fairly early on in Simonetti.

The dictates of the era’s Romantic painting, which depicted the past and episodes of homeland history, led to reconstructions of settings and characters in the most historically faithful manner possible and that pushed artists to collect antique clothes, objects and furnishings.

Following the example of his maestro, Mariano Fortuny, Simonetti soon built up a large collection, which he then began to sell on in part.  In 1883, he organized an important auction. This was a great success due to the interesting nature and rarity of the objects proposed.  From this moment onwards, he became increasingly interested in art dealing and, in 1889, he moved to Palazzo Odescalchi (in Rome’s Via Vittoria Colonna) which he bought from Prince Baldassare Odescalchi in 1904.  Here he opened a Gallery destined to become the point of reference for a large international clientele.  Figures such as the financier, John Pierpoint Morgan Jr., and the magnate, William Waldorf Astor, were flanked by a great crowd of cultured collectors from the aristocracy and emerging middle classes.  Art experts and museum curators such as Wilhelm von Bode and Ludwig Pollak were very close to him and objects with a Simonetti provenance were bought by the world’s most important collections and museums.