A Spanish army under Gonzalo Fernández de Córdoba besieged the Palatinate fortified city of Frankenthal and its mostly English garrison commanded by John Burroughs.

The siege lasted from 1621 to March 20, 1623, when King James I ordered the city to surrender.

[2] In the early seventeenth century, the city's fortifications were upgraded by Frederick IV, Elector Palatine in preparation for war.

Frederick also refortified Heidelberg and created the fortress-city of Mannheim.

On May 23, 1618, the Kingdom of Bohemia rose in revolt against Ferdinand II, Holy Roman Emperor and offered the crown to Frederick V, Elector Palatine, who, by accepting the Bohemian offer, brought the Electorate of the Palatinate into the war, thus broadening the conflict.