The important owners, whose rule on the estate is connected with extensive building activities, were the Smiřický family, one of the richest in Bohemia in the second half of the 16th century. Sigismund of Smiřice bought Náchod in 1544 and it remained in the possession of this family until 1620, when it was confiscated as part of the post-Whitehorse confiscations for the Smiřice's participation in the Estates' Revolt. The last male member of the family, Albrecht Jan, who inherited the Náchod estate in 1614, was an active participant in the Estates' Resistance, personally taking part in the May 1618 defenestration and was one of the thirty directors. His promising career was, however, prematurely ended by his unexpected death in November 1618. The extensive Smiřice inheritance, and thus the Náchod estate, was acquired by his sister Margaret Salome, and the so-called Winter King Frederick V of the Palatinate spent his last night in Bohemia in the local castle. Margaret Salome also left Bohemia at the same time. Among the 27 Czech leaders executed in the Old Town Square on 21 June 1621 was Tobias Štefek of Koloděj, a townsman from Náchod, a member of the Estates Directory and regent of the Smiřický estate.

In 1623 Magdalena Trčková of Lípa bought the Náchod manor and a few years later ceded it to her son Adam Erdman Trčka. Adam was the last owner from the Czech nobility. His brother-in-law was Albrecht of Wallenstein, the commander of the imperial armies, whose mother was also from the Smiřický family and who was perhaps born at Náchod castle in 1583. Adam faithfully stood by his relative until his death on 25 February 1634, when he was murdered together with him in Cheb.