The Gamma-Gerät was the most powerful piece of artillery fielded by the Imperial German Army, but due to its extreme weight was mostly immobile and could only be emplaced near permanent rail lines.

Allied counter-battery fire and internal detonations caused by faulty ammunition reduced the number of extant Gamma-Gerät howitzers to a single gun by the end of World War I.

In response, military architects began placing forts in rings around cities or on a frontier to block approaching armies.

[1][2] The German Empire also fortified its borders, but Chief of the General Staff Helmuth von Moltke the Elder desired to break through Franco-Belgian fortifications.

[5] Moltke began requesting more powerful guns that same decade, which his successor, Alfred von Schlieffen, saw as key to his plan to quickly defeat France by sweeping through Belgium.

In 1893, the German Army's Artillerieprüfungskommission [de] (Artillery Test Commission, APK) formed a secret partnership with Krupp to supervise development of a weapon that could break Franco-Belgian fortresses.

The Beta-Gerät was adopted into service in 1897 as the schwere Küstenmörser L/8, a cover name concealing its true purpose,[a] making it Germany's first large artillery piece to have a breech and a recoil system.

Further studies conducted by the APK in the mid-1890s showed that the Beta-Gerät could not penetrate the armor of modern Franco-Belgian forts, even with revised shells.

[7] Helmuth von Moltke the Younger, Chief of the General Staff since 1 January 1906,[8] sought a larger siege gun.

[b] Emplacement required the clearing of all nearby vegetation and the digging of a rectangular 2.25 m (7.4 ft) pit and the spinning of a spur off the nearest permanent railway to the site.

Beginning in early 1916, German siege guns began to suffer internal explosions due to faulty ammunition.

[17] The German defeat at the First Battle of the Marne prevented the siege guns at Maubeuge from being sent against Paris, so they were sent back into Belgium to Antwerp.

The next day, KMK Battery 2 opened bombardment against the Fort de Wavre-Sainte-Catherine, which was destroyed on 29 September by a magazine detonation caused by a 42 cm shell.

[19] With the fall of Antwerp, KMK Battery 2 was attached to the 4th Army to aid in its capture of the Channel ports, and occasionally shelled Nieuport, Ypres, and Diksmuide.

[21] On 27 February 1915, KMK Battery 1 arrived on the Eastern Front with the 8th Army and joined the ongoing attack on Osowiec Fortress.

On 6 October 1915, KMK Batteries 1 and 4 opened fire on Serbian fortifications east of Belgrade to support the crossing of the 11th Army, made the next day.

[22] KMK Batteries 1 and 4 were transferred back to the Western Front in early 1916 and were assigned to the 5th Army for the upcoming Battle of Verdun.

In 1917, KMK Battery 8 were denuded of their Gamma-Gerät guns by internal explosion and Allied counter-battery fire and was reequipped with an ineffective war-time iteration of the M-Gerät.

Two were surrendered to the United States and the third,[27] the final Gamma-Gerät, was disassembled and hidden from Allied inspectors in Krupp's Meppen facilities.

The Gamma-Gerät was placed in storage after the fall of France until early 1942, when it was sent to bomb the fortresses of Sevastopol, which it shelled from February until exhausting its munitions on 13 June.