At the beginning of the 15th century, the fortress was owned by Mikuláš (Mikeš) Divůček (Divoký, which means "Wild”) of Jemniště and Cimburk. He entered the services of King Václav IV. and at his court he also met Jan Hus. He belonged to his closest friend and in 1414 he warned him against the trip to Constance. He, however, disagreed with the upheaval which after Hus’ burial spread across the country. Therefore, after the death of King Václav IV, he took the side of his heir King Zikmund and soon became one of the Hussites’ opponents. He is responsible for murdering the followers of "the Chalice”, which occurred from 1419 across the whole of Bohemia primarily in Kutná Hora. In March 1420, he was defeated by Jan Žižka in the battle of Sudoměř and later also at Vítkov and at Vyšehrad (1420). Therefore he fell in this favour with Zignmund. He died in 1423 in Moravia. Reports concerning Jemniště became less and less frequent during the Hussite wars. Another record comes from 1534 when Mikulaš Kamberský of Kamberk is reported as being the owner.
Prior to 1593, the fortress was purchased by the Aristocratic Family of Říčany. It is possible that, at this time, the fortress was rebuilt to become a more comfortable Renaissance seat. The original home of knights disappeared and was replaced with by a comfortable small chateau with four wings. During the Thirty Years War, the estate was plundered several times. In 1666, the nobleman sold Říčany and Jemniště together with another six villages that belonged to the estate. Over several decades, the owners of the estate changed several times. In 1717 the estate was bought by Count František Adam of Trauttmansdorff (†1762), originally from an old Steiner family in Germany. After the new Baroque-style chateau was constructed, the family moved out of the fortress and the fortress was used to accommodate senior officials. Since then, every owner of the new castle also became the owner of the old castle.
In 1995, both castles underwent a process of restitution which meant that, after more than 50 years, the property was returned to the Sternberg family. Because both castles were handed back to the family in a rather dilapidated state (the new castle when compared to the old castle was really as good as new), Petr and Jiří Sternberg decided to submit it to a long-term lease. The couple, Jana and Otto Černý became the tenants, who have been doing their utmost to reconstruct the chateaus.