First Rosenbergs – Petr, Jošt, Oldřich and Jan founded the Augustinian monastery, built the little Třeboň castle, awarded the town the rights of royal towns and thanks to their relationships with the court of Charles IV. enabled overall economic and cultural prosperity of the town.
Master of the Třeboň altarpiece (latter half of the 14th century), author of the Gothic panel paintings of mid-European importance, lived and worked in the Třeboň monastery. Around the year 1380 he created an altarpiece with five panels for the newly built monastery church of St. Giles. Three panels remain today: “Christ on the Mount of Olives”, “The Tomb of Christ” and “Resurrection“ and they are part of the collections in the National Gallery in Prague.
Petr IV. of Rosenberg (1462–1523) was a Czech aristocrat, the ruler of the House of Rosenberg and the highest hetman of the Czech Kingdom. He focused on the complex economical development of the Rosenberg domain, the rise of silver and gold mining and had merit in the development of fish pond building. In his service worked the excellent Štěpánek Netolický.
Štěpánek Netolický (around 1460–1539), originally an assistant forester, later a builder and hetman of the Třeboň domain, one of the major Czech fish pond builders. His ability to perceive the landscape enabled him to change the inhospitable character of marshes and wetlands in the Lužnice River basin and give it a new system. Among his best-known works are Opatovický, Kaňov and Horusický fish ponds. To supply fish ponds with fresh water he built the unique Golden Canal which has been the main supply of water to fish ponds of the Třeboň basin ever since. As a respected builder and surveyor, he was also responsible for the modernization of Třeboň fortifications including the town gates in the years 1525–1527.
Mikuláš Ruthard of Malešov (? – after 1576), pupil and successor of Štěpánek Netolický, hetman of the Třeboň domain, built many fish ponds mainly near Chlum u Třeboně and Lutová. His Staňkovský fish pond still holds the record for the deepest pond in the Czech Republic. He founded farmsteads and initiated new farming methods. His contribution to fish pond farming is the introduction of three-stage carp breeding. Ruthard´s breeding plan remained in use until the 19th century.
Vilém of Rosenberg (1535–1592), Knight of the Golden Fleece, was one of the most important European politicians of the latter half of the 16th century, he even ran for the position of Polish King. He took over the government of the domain at the age of 16. At that time, economic conditions were so good that he could realize his generous plans of supporting the church, town administration, crafts and building activities in the town. Vilém himself travelled around Europe and gained a lot of experience and expertise. He had abilities and ambitions for high positions and as the High Burgrave of Prague Castle was the second most important man in the state, after the King. Under his reign there was an overall expansion of the town and the whole domain. Thanks to him, all the courageous plans of Jakub Krčín, the fish pond builder, were realized.
Jakub Krčín of Jelčany and Sedlčany (1535–1604), a regent of the Rosenberg domain, a gifted builder of tens of South Bohemian fish ponds, a rigorous and arduous implementer of his own ideas into practice. He entered the Rosenberg services at the age of 26. Eight years later, thanks to his courage, determination and organization skills, he was named the regent of the whole Rosenberg domain and managed to enforce development in different areas of his purview. He continued the work of Štěpánek Netolický, building many fish ponds himself (e.g. Spolský, Potěšil) or enlarging them (e.g. Opatovický, Záblatský, Dvořiště, Naděje, Skutek). His courageous intent of building a large fish pond in front of the southern gates of the town caused him many problems. Only the following centuries proved his decision was right. Krčín´s fish pond Nevděk (Ingratitude), now known as Svět (World), is inherently connected with Třeboň. The most important work crowning the whole water system in the Třeboň basin was the artificial stream of the New River and the Rožmberk fish pond.
Dr. John Dee (1527–1608), renowned English mathematician, astronomer and astrologer, counsellor of Queen Elizabeth I. and court alchemist of Emperor Rudolf II., worked together with the alchemist Edward Kelly (1555–1597) at the court of Vilém of Rosenberg between 1586 and 1589.
Petr Vok of Rosenberg (1539–1611), last of the Rosenbergs, was an unusual personality of his time. In his youth he was a slim, tall elegant man with good manners. He liked horse riding and fencing, had a sense of humour and was a fan of knightly sports. Together with his brother Vilém they travelled around the whole of Europe on their chivalrous journeys. He took over after his brother in 1592 and then sold Český Krumlov to King Rudolf II., after which he moved his court to Třeboň castle in 1602 at the age of 63. Between 1605 and 1606 he commissioned the building of the library, picture gallery and pharmacy. At the same time, the south-east wing of the castle was adapted. His library and art collection were one of the largest in Europe. Petr Vok also developed the town´s fortification. His foresight in arming Třeboň saved it from pillaging by Passau mercenaries. He generously paid off the Passau army plundering the countryside between Budějovice and Třeboň. He donated the old Rosenberg silver treasure which he had melted and made into coins. Petr Vok of Rosenberg died at the age of 72 on 6th November 1611. He became a legend, a model of a generous benefactor and exemplary Renaissance knight, and a beloved ruler. With his death, presumably the most famous epoch of Třeboň ended.
Václav Březan (1568–1618), Rosenberg historiographer, archivist and librarian, excelled in universal education and broad knowledge. He entered the services of Petr Vok in 1593 and was charged with the administration of the large Rosenberg archives, that he carefully organised. Březan also administrated the renowned Rosenberg library considered to be the largest and best aristocratic library in central Europe. It contained over 11, 000 volumes. He also compiled a handwritten systematic catalogue unprecedented in terms of range and quality. After Petr Vok had relocated to Třeboň, Březan devoted himself to writing the five-volume Historie Rožmberská (Rosenberg History) in which he described the history of the family from its beginnings to the times of the last rulers.
