The first castle in Zug was probably a wooden manor house built around 1000 and owned by a ministerialis family in service to either the Counts of Aargau or of Lenzburg. Based on archaeological excavations, it was built on an island between two small streams and surrounded by a wooden palisade. While the local nobleman occupied the house and island, his men built a village along the streams. Later the steams were dammed to prevent flooding.
Around 1555 Johannes Zurlauben had the old wall demolished and a decorative wall built around the castle. He had a half-timbered structure built on the west side of the tower. In the 16th century, the old Habsburg living quarters were expanded and connected to the Zurlauben structure.
The castle was not damaged in the siege and became a Confederation castle. After Zug joined the Confederation as a full member, the castle gradually lost its importance.
The museum in the Castle of Zug tells the history of the city and the canton of Zug. Zug Castle has been home to the museum of cultural history for the city and the Canton of Zug since 1983.
The castle was purchased by the municipality of Zug in 1945 from the Hediger family and later renovated in 1982. Recently, the castle contained the Zug town and cantonal museum’s permanent collection along with other exhibits. In 2012, the museum was closed for refurbishment and re-opened in November 2013 with a new permanent collection.