Ernst IV von Gleichen
Ernst IV von Gleichen (1198–16 May 1277) was a son of Count Lambert II and Sophie of Weimar-Orlamünde, and after the family partition he headed the Gleichen line of the comital house. A knight as well as a count, he married two Danish noblewomen in succession, Ingeborg Pedersdatter and Margrete Olufsdatter.
His sons included Erwin III and Heinrich IV, who served as a knight and royal councillor in Sweden; under Heinrich's grandsons this line later split into the Blankenhain and Tonna branches.