Complex sentence: Considered the best of Russia's portrait photographers, Levitsky photographed four generations of the Romanov dynasty (in 1877, he was awarded the title Photographer of their Royal Majesty) and legendary personalities that included U.S. President Millard Filmore (1800-1874) and European Royalty.
Split into simpler sentences: Considered the best of Russia's portrait photographers, the Levitsky studio photographed four generations of the Romanov dynasty (in 1877, it was awarded the title Photographer of their Royal Majesty). It took photos of legendary personalities that included U.S. President Millard Filmore (1800-1874) and European Royalty.