Bournonville marched south to the Imperial City of Strasbourg, giving him a base for an attack on Alsace but before doing so, he awaited the arrival of 20,000 troops under Frederick William. To prevent this, Turenne made a night march that enabled him to surprise the Imperial army and fought them to a standstill at Entzheim on 4 October. As was then accepted practice, Bournonville halted operations until spring but in his &lt;a href="Turenne%27s%20Winter%20Campaign"&gt;Winter Campaign 1674/1675&lt;/a&gt;, Turenne inflicted a series of defeats culminating in Turckkeim on 5 January. As a result, he prevented an Imperial invasion and secured Alsace.