César Franck (1822-1890) was a Belgian-French Romantic composer, organist, and teacher, known for revitalizing French instrumental music with German-inspired depth, famous for works like his Symphony in D minor and Violin Sonata, who became a revered professor at the Paris Conservatoire, influencing students like Vincent d'Indy and Henri Duparc. Despite early struggles, he found his voice later in life, combining rich harmonies and a unique "cyclic form" (reusing themes) in his distinctive style, leaving a legacy of profound, spiritual music.