[1] At the imminent prospect of war in December 1863, he was asked to take over the fort again as commander in Fredericia, to which he was immediately ready, although the fortress, despite the works used thereon, was still in poor condition at the time.

[5] It ordered him to relentlessly put the fortress on the defensive, and he then seized upon the old zeal and tenacity, so that when the Prussians and Austrians in March appeared outside its ramparts, it was able to endure a siege.

However, there wasn't an actual siege as the Prussians and Austrians confined themselves to a bombardment, and Lunding then easily had to reject General Ludwig von Gablenz's subsequent call for surrender.

After Dybbøl's fall on 18 April, however, the government decided to evacuate Fredericia, and Lunding received the order to do so on the 26th of the same month, which was such a hard blow for him that he relinquished command and had someone else lead the escape.

[1] That same year he resigned as commander and was put à la suite in the army, while the Reichstag that same winter granted him a special pension in recognition of his merits of the fatherland.