While Chopin always considered himself to be of Polish nationality, he was almost equally at home in France. Not only had his own father been a Frenchman, but Paris in the nineteenth century was home to a large community of expatriate Poles. Furthermore, the intellectual life of this city was traditionally sympathetic to the cause of Polish nationalism, a cause which often took Chopin as one of its musical figureheads. In this way, Chopin's cello sonata is as much of a work of Paris as of Poland. It also came at a pivotal transition point for Chopin, completed around the time his relationship with writer George Sand. Other than, of course, the piano, the cello was one of Chopin's favored instruments, and his close friendship with Parisian cellist Auguste Franchomme produced several works.