At that time, they probably proceeded to rebuild the existing original castle and expand it with a large courtyard with a Gothic chapel, encircling the castle with fence walls with a gallery and battlements, farm buildings, workshops and a tunnel entrance. The rulers, as well as the Stiborors, made sure that the castle was a fortress that could withstand the onslaught of all enemies. King Sigismund donated the castle estate to Michal Orsag de Gut in 1436. This family also took care of the castle and its equipment. As he was in his hands for 130 years, he left traces on him in the form of further modifications. Rapid development of firearms in the second half15. century. encouraged the construction of a second wider fence, which in the south resulted in an advanced fortified bastion with cannon shots. When the last member of the Orságov family - Krištof Orság died without descendants, the castle estate fell to King Maximilian I, who in 1569 gave it to Uršula Kanižajová's widow after Tomáš Nádašdy. Her son František Nádašdy I. bought the castle estate from the monarch in 1602. After his death in 1604, the estate was inherited by his wife Alžbeta Báthoryová - known as the bloody lady of Čachtice, who lived in the manor house in Čachtice. After Elizabeth's death, inheritance disputes arose between her children - her son Pavel Nádašdy and daughters Katarína and Anna, married to Juraj Druget and Mikuláš Zrínský.