I think one thing that is often forgotten is that until the Renaissance, "artists"... painters, sculptors, architects... were all thought of largely as skilled craftsmen. The "visual arts" were not even acknowledged as being among the "liberal arts". A great majority of artists were illiterate or limited with regard to their abilities with regard to reading and as such almost wholly dependent upon the theologians and other educated advisers or consultants with regard to iconography. Artists were also largely limited with regard to an exposure to art beyond the confines of their immediate surroundings. We are speaking of an era before photographic reproductions... or even printed reproductions of art. We are also speaking of an era when travel was difficult, dangerous, and rare.
A number of major artists of the Renaissance including Brunelleschi, DaVinci, Michelangelo, Raphael, Durer, etc... were responsible for beginning the shift from the notion of artist/craftsman to artist as an educated, creative individual (The Renaissance Man). This transition, however, was rather slow. Well into the Baroque era few artists in the north of Europe enjoyed recognition beyond that of master craftsmen.
The real shift takes place with the Dutch Baroque and the shift away from the patronage system toward a capitalist market system. Rather than making art in response to the demands of the wealthy patron, artists created what they wished and attempted to find an audience. Ultimately, this offered no more freedom than the old system. The artist who wished to sell was forced to gear his or her art toward the demands of the buying public. In some ways, the system of patronage offered a greater degree of freedom for the artist who was able to develop a strong relationship with a wealthy patron.
Of course artists have always been free to create whatever they wish... within the limitations of their own financial ability. My studio mate continues to churn out bleak, 14-foot canvases that address the Holocaust by the hundreds... but the audience/buyers are equally free to choose that which they wish to support... and they choose not to buy his paintings. It has probably only been within the last century or so that individuals have had the freedom, the free-time, and the ability to fund their own art as a personal passion (not to say hobby) without the need to make money.