Giovanni Francesco Barbieri, ‘Il Guercino’ (1591 – 1666): A Master of Dramatic Light and Emotion Giovanni Francesco Barbieri, universally known as Il Guercino—a nickname derived from the “squinter” or squint referring to his distinctive eye condition—stands as a pivotal figure in the transition between Mannerism and Baroque painting. Born in Cento, near Bologna, in 1591, his life was one of relentless artistic exploration, marked by both periods of intense experimentation and ultimately, a refined mastery of classical forms. Unlike many artists of his time who benefited from established patr…