[1] The idea for an army of Alsace originated with the Duke of Feria in November 1632, when he received a request from Isabella Clara Eugenia, the governor of the Habsburg Netherlands, to provide for the defence of the County of Burgundy.
Already charged with protecting the Milan–Flanders route for the planned march of the Cardinal-Infante Ferdinand of Austria, wrote to Madrid on 4 February 1633 proposing to raise an army of 15,000 men for service in Germany.
[1] Diplomatically, it was necessary to secure the approval of Emperor Ferdinand III, Elector Maximilian I of Bavaria and General Albrecht von Wallenstein.
[1] On 5 July, with the army almost formed, the emperor, acting on Wallenstein's advice, refused to permit it to operate in Alsace.
By mid-August, however, he had been persuaded by Spanish representatives, the Count of Oñate and Marquis of Castañeda, to change his mind and permit the army freedom of operation.