The siege of Frankenthal was a siege of the Palatinate campaign during the Thirty Years' War. 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 20 March 1623, when King James I ordered the city to surrender.
== Background == 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. Frankenthal had an important strategic role within the Electorate of the Palatinate. On 23 May 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.
