Months Past The Treaty of Westphalia On 24 October 1648, the Treaty of Westphalia was signed, marking the end of the Thirty Years' War. Richard Cavendish | Published in History Today Volume 48 Issue 10 October 1998 To continue reading this article you will need to purchase access to the online archive. Buy Online Access Buy Print & Archive Subscription If you have already purchased access, or are a print & archive subscriber, please ensure you are logged in. Please email digital@historytoday.com if you have any problems.