Cosway's flamboyant personality, eccentric mysticism, and brilliant marriage to Maria Hadfield during the 1780s brought him celebrity and notoriety. He was the principal recorder of the Prince of Wales' image from 1780 to 1808, as well as having exerted a great influence on his patron's artistic taste and collecting during that period. Perhaps Cosway's greatest achievement, however, was as a connoisseur, virtuoso, and collector - particularly of Old Master painting. He was undoubtedly the most important, influential, and fashionable portrait miniaturist.