Tertius Lydgate is a fictional character from the novel Middlemarch by George Eliot. He is a young and ambitious doctor who arrives in the provincial town of Middlemarch with hopes of making a significant impact on medical practice. Lydgate is characterized by his progressive ideas and desire to reform medicine, but he often struggles against the limitations of his environment. Throughout the story, Lydgate's personal and professional life becomes increasingly complicated. His relationships, particularly with Rosamond Vincy, reveal the challenges he faces in balancing his ideals with societal expectations. Ultimately, Lydgate's journey reflects the broader themes of ambition, disillusionment, and the constraints of social class in 19th-century England.