William Gregory 

This is a portrait of William Gregory by John Riley, an English painter active in the late 17th century. The sitter is depicted in a formal pose, wearing a white collar and a red and white robe. The painting likely dates from the latter half of the 17th century, as Riley's artistic style and the subject's clothing are indicative of this period. Riley was known for his ability to capture likenesses, and this portrait exemplifies his skill. The portrait's composition and lighting highlight Gregory's features, creating a realistic and engaging image. John Riley is a less well-known figure, but his portraits are known for their accuracy and naturalism.