[2][3] He continued his uninterrupted military service for the next 40 years of peace, rising to the rank of General of the Infantry.

In 1829, Barnekow was second lieutenant and from 1831, he was in the 39th Lower Rhine Fusilier Regiment [de] and from 1833 to 1836, he was the adjutant of the II Battalion.

[4] He was part of the 1st Division in the 1st Army Corps as the commander of the 2nd Infantry Brigade under Adolf von Bonin.

[2] Ten days later, Barnekow led the right wing in the Battle of Saint-Quentin, with which he entered the city as the first unit and forced the French to a hasty retreat, in which large parts of the northern army were then captured.

[2][3] For his service in the war, he received the Iron Cross, 2nd and 1st Class and the Oak Leaves for Pour le Mérite.

[3] On August 2, 1876, on his 50th anniversary of service, Barnekow received the Grand Cross of the Order of the Red Eagle with oak leaves and swords on the ring.