While his work is noted for its quality and beauty, his perfectionism and constant reworking of his paintings meant that his extant output is sparse.
As a boy he was placed as a apprentice to a painter Giacomo Triga, but then passed on to work in the school of the Genoese Giovanni Battista Gaulli called Il Baciccia.
There he acquired his nickname "il Creatura di Baciccia" on account of his youth and small stature.
In 1707, at age 13, he won a drawing competition sponsored by the Accademia di San Luca.
which resulted in the painting The Immaculate Conception Worshipped by Saints John Crysostom, St. Francis and St. Anthony of Padua, now in the church of Santa Maria degli Angeli at Rome, which was only barely finished at the time of his death and which was eventually executed in mosaic for St Peters.