[1][3] The Landgrave of Hesse-Kassel, William V, as a Protestant ally of Sweden had campaigned in Westphalia, Ruhr area and the Sauerland, successfully reducing the imperial presence there.

[4] The battle was preceded by a Swedish siege of the nearby imperial-held town of Hameln, laid in March 1633 with support of Hessian and Lüneburgian troops.

[5] On 8 July, the Swedish army commanded by George, Duke of Brunswick-Lüneburg[3][6] and Marshal Dodo zu Innhausen und Knyphausen[3][6] faced an Imperial relief army commanded by Field Marshal Jobst Maximilian von Gronsfeld,[3][6] Count Jean de Merode[3][6] and Lothar Dietrich Freiherr von Bönninghausen.

[nb 1][7] The left wing of the Swedish forces was commanded by the general of Landgraviate of Hesse-Kassel and later imperial field marshal Peter Melander.

[13] As a consequence, Sweden's and Hesse-Kassel's forces stood alone against a growing anti-Swedish, pro-Habsburg coalition in 1635 - a disequilibrium eventually stirring France's intervention in the Thirty Years' War.