Rembrandt van Rijn, the most important artist of the Dutch Golden Age, was a master of the 'chiaroscuro' technique—the use of strong contrasts between light and dark to create a sense of volume and drama. His most famous work, 'The Night Watch' (1642), is a prime example. Interestingly, the painting is not actually a night scene; the dark appearance was caused by layers of dirt and varnish that accumulated over centuries. After cleaning in the 1940s, it was revealed to be a daytime scene of a city guard. Rembrandt’s genius lay in his ability to capture human emotion and character; unlike many of his contemporaries who sought to idealize their subjects, Rembrandt painted people with all their imperfections, including himself in over 80 self-portraits that document his life from youth to old age. His work influenced generations of artists and remains celebrated for its psychological depth and innovative use of light.