The University of Groningen was founded, initially only for religious education. In the same period the city expanded rapidly and a new city wall was built. That same city wall was tested during the Third Anglo- Dutch War in 1672, when the city was attacked fiercely by the bishop of Münster, Bernhard von Galen. The city walls resisted, an event which is celebrated with music and fireworks on 28 August (as "Gronings Ontzet" or "Bommen Berend").
The city did not escape the devastation of World War II. In particular, the main square, Grote Markt, was largely destroyed in April 1945, at the Battle of Groningen. However, the Martinitoren, its church, the Goudkantoor, and the city hall were not damaged. The battle there lasted several days.