Pieter Frederik van Os came from a well-known family of painters. His grandfather, Jan van Os, was a painter of flower and fruit still lifes, as were his aunt Maria Margaretha and his uncle Georgius Jacobus Johannes. His father was the famous cattle painter Pieter Gerardus van Os. As was customary at the time, young Pieter Frederik was taught by his father. He then specialized in painting animals, especially horses in all their doings: workhorses, hunters, draft horses and racehorses. At an early age, Van Os made a journey through Gelderland, to Belgium and to Germany, especially through the hilly area around Cleves. From Amsterdam he settled in Haarlem in 1839, where he developed into a beloved animal painter. Now and then he upholstered the landscapes of painter friends with horses and dogs.