Westphalia, Hesse and Lower Saxony Electoral Saxony Brandenburg Silesia East Prussia Pomerania Iberian Peninsula Naval Operations The siege of Cassel (March 1761) was a failed attempt by Duke Ferdinand of Brunswick to capture French-held Kassel, the capital of Hesse-Kassel.

Brunswick lifted the siege after forces of the Duc de Broglie inflicted heavy casualties on his forces at the Battle of Grünberg, making continuation of the siege untenable.