A contribution to the history of the Old Prussian Infantry Regiment Duke of Brunswick (IR No. 21).

Infantry Regiment No. 21 was formed in 1713 from various regiments returning from Dutch service, namely surplus personnel from five regiments. The canton (replacement district) lay in the Principality of Halberstadt, namely — in part — the counties of Wernigerode, Ilsenburg and Hohenstein and the towns Quedlinburg, Gröningen, Wegeleben, Halberstadt, Wernigerode, Derenburg, Bleicherode, Schsa, Ellrich and Beneckenstein.

In the Seven Years' War the unit fought at Lobositz, Kolin, in part at Roßbach, Kunersdorf, Maxen and Torgau. At Lobositz the regiment fought with distinction, but at Kolin it suffered very heavy losses. Afterwards the regiment was restored by good replacements from the canton, but was no longer capable of major achievements (according to Hans Bleckwenn).

The garrison was ultimately Halberstadt (previously also Quedlinburg). The formation was lost through the surrenders of Prenzlau on 28 October 1806 and Magdeburg on 11 November 1806.

Among the regiment proprietors of the formation General von Hülsen (until 1767) is particularly well known. Hans Bleckwenn comments on this as follows: "As a personality the 'old Hülsen' stands out. He was not merely a dandy, but a commander of troops of rank; determined bravery at Kolin and prudent foresight in 1760 in the defense of northern Saxony against a large superior force attest to it. Torgau was his day of honor — in the evening of the unsuccessful struggle he took over the command from the King; when in the darkness the attack of Zieten's corps nevertheless became effective, the completely exhausted man — 67 years old and just wounded — had himself lifted onto a cannon to once more display the 'battalions' of stragglers gathered by Lestwitz, with success. He had a keen eye for the usefulness of his subordinates: Gaudi and the later all-powerful General-Adjutant v. Anhalt were his aides, and numerous documents attest to his efforts to promote deserving officers." Quoted from the text to the aforementioned plate.