Complex sentence: Vasil Nikolov Zlatarski was a Bulgarian historian-medievist, archaeologist, and epigraphist, acknowledged as one of the greatest names in the Bulgarian Middle-Age history with his three-volume "History of the Bulgarian State in the Middle ages".
Split into simpler sentences: Vasil Nikolov Zlatarski was a Bulgarian historian-medievist, archaeologist, and epigraphist. He is considered one of the greatest names in the Bulgarian historiography with his three-volume "History of the Bulgarian State in the Middle ages".