[3] The donation was made in gratitude to the Abbot of St. Gall for rescuing Rudolf from his sons in law, who were holding him prisoner at Heitnau Castle in an attempt to receive their inheritance early.

After his son Ulrich died childless, the title to the castle transferred fully to the Abbey.

While there is no record of an attack, the stone walls show evidence of a massive fire and many wooden beams date to between 1414 and 1425, indicating that the castle was probably damaged.

Her new husband, Burkhard Schenk von Castell, bought out the shares of the remaining heirs.

During the Thirty Years War, on 6 September 1633, the castle was attacked and captured by a Swedish army, though it only suffered minor damage.

[2] After the 1798 French invasion of Switzerland and the creation of the Helvetic Republic the Abbey's estates, including Hagenwil, were nationalized.

With the collapse of the Republic and the 1803 Act of Mediation, the Canton of St. Gallen was created, incorporating many of the Abbey's former estates.

Two years later, in 1805, the Grand Council of the Canton decided to sell off much of the former estates including Hagenwil.

[4] The castle complex is a rough square surrounded by an 18th century 3.2 meters (10 ft) deep water filled moat.