Archbishop Loftus left the castle to his son, Dudley and it then passed to his son Adam in 1616. During Adam's ownership, the castle came under siege in the 1641 rebellion. It was able to hold out against the Confederate army when the surrounding country was overrun. Adam Loftus opposed the treaty of cessation in order the stop the fighting between the Irish Confederates and the English Royalists. Consequently, he was imprisoned in Dublin Castle.