Henry III "the Great" was the count of Sayn (1202–1246), a county located near the Sieg River in northern Rhineland-Palatinate, Germany. Henry III shared the first year of his reign with his uncle, count Henry II, as he and his father Eberhard II had co-ruled the county. Gottfried II had been a regent from 1181 and continued until his death in 1220. John, count of Sponheim-Starkenburg, was regent from 1226 until Henry's death in 1246.