Quast stemmed from a family of old Anhalt nobility. He was the son of the Prussian state conservator-restorer Ferdinand von Quast and his wife Maria, née von Diest. Her father was Prussian Lieutenant General Heinrich von Diest. On 21 Jun 1877 Quast married Alexandrine Freiin von Paykull.
Career
On 19 July 1870 he joined the 2nd Regiment of Guards Grenadiers and fought with it in the Franco-Prussian War. On 12 January 1871 Quast was promoted to Sekondeleutnant and received the Iron Cross 2nd Class. On 23 September 1879 he was promoted to Premierleutnant. 1887 followed a promotion to Hauptmann, and in 1894 he was made a Major and assigned as battalion-commander in the 2nd Guards Infantry. In 1901 von Quast was promoted to Oberstleutnant and assigned to the staff of 1st Guards Grenadiers before becoming commander of his old 2nd Guards Grenadiers with the rank of Oberst on 18 April 1903. As General-major he took command of the 39th Infantry Brigade at Hannover on 21 May 1907. The following year he was at first assigned as commander of the 3rd Guards Infantry Brigade in Berlin, then assigned to the 2nd Guard Infantry Brigade in Potsdam. On 27 July 1910 Quast was tasked with the command of the 36th Infantry Division in Gdańsk. Shortly afterwards he was promoted to Generalleutnant and given command of the 6th Infantry Division in Brandenburg City. In March 1913 Quast was named commanding general of the IX Corps in Altona, Hamburg.
Fighting in the Battle of Tirlemont, von Quast was promoted to General der Infanterie on 19 August 1914. In 1916 he participated in the Battle of the Somme where he and his corps were positioned in the southern sector near Péronne. His stern defensive and his organizatorial skills were noticed and he received the Pour le Merite from the hand of Emperor Wilhelm II on 11 August. In January 1917 Quast was assigned to lead the prestigious Guards Corps, a command he held until September when he was named commander of the 6th Army. On 10 April 1918 he was awarded the oak leaves to his Pour le Merite.
After the war
After the fighting ended and the demobilisation of the high command von Quast relinquished his command and put in the leadership reserve. On 18 January 1919 he was assigned command of Grenzschutz-Armeeoberkommando Nord as part of the Provisional Reichswehr at Königsberg. After the Treaty of Versailles was signed von Quast requested his retirement and finally retired on 7 July 1919. He died in Potsdam.
