In the Thirty Years' War after the Battle of Lutter on 17/27 August 1626&lt;a href="Old%20Style%20and%20New%20Style%20dates"&gt;O.S./N.S.&lt;/a&gt; the Catholic Leaguist forces invaded the Prince-Bishopric of Verden and threatened the neighbouring Bremen Prince-Archbishopric. Meanwhile Christian IV of Denmark, Duke of Holstein, since May 1625 officiating in the latter of his functions as Circle Colonel (commander-in-chief) of the joint troops of the Lower Saxon Circle, and allied with the Anglo-Dutch war coalition, concentrated Lower Saxon troops in the prince-archbishopric and ordered additional Dutch, English and French troops to land in the prince-archbishopric. By 1627 Christian IV had de facto dismissed his cousin Administrator regnant John Frederick from the Bremian see.