Where Storm Clouds Gather by Anthony Saunders features Bf109s of JG4 over the Mosel river.

When the prototype of Willy Messerschmitt's radical all-metal single-seat monoplane fighter first took to the air in May 1935 little did onlookers realise they were witnessing the birth of one of the world’s most iconic aircraft.

Sporting sleek lines, a closed cockpit and retractable landing gear the Bf109 was soon wowing the crowds at the 1936 Berlin Olympics, an ominous prelude to its worth in battle after its introduction into service with Germany’s Condor Legion in the Spanish Civil War the following year. It was clear to friend and foe alike that this agile, well-armed little fighter was superior to anything else in the skies and by the outbreak of World War II the Bf109 formed the backbone of Hitler’s new Luftwaffe. With battle-hardened pilots well-prepared for success in Poland, the Low Countries and France, they were now ready to duel with RAF Fighter Command during the Battle of Britain.

Bf109s also served in the Balkans campaign, they flew against the Soviets on the bitter Eastern Front and fought in the searing heat of the North African desert before being pressed into service defending the Reich from the US Eighth Air Force’s massive daylight bomber formations. On every front over occupied Europe, Allied pilots would invariably encounter the Bf109 – one of the few aircraft to see front-line service throughout the war.

Continuously improved and upgraded more Bf109s were produced than any other military aircraft in history, with one exception, the Soviet’s Il-2 Sturmovik. The much-feared fighter was flown by the highest scoring Aces of all time – men such as top-scorer Erich Hartmann (credited with 352 aerial victories), Gerhard Barkhorn (301 victories), Günther Rall (275 victories) and the highest-scoring ace in North Africa, Hans-Joachim Marseille (158 victories).

 'Where Storm Clouds Gather', portrays the Bf109s of JG4, one of the many Luftwaffe units that took part in the German Ardennes offensive that began in December 1944. In the foreground is Hauptmann Ernst Laube, Gruppenkommandeur of IV./JG4, seen leading his men along that part of the Mosel river dominated by the seemingly unscathed Cochem Castle. They are returning to base after a hard-fought encounter in which, outnumbered by Allied fighters, they are relieved to have survived yet another day.

Where Storm Clouds Gather by Anthony Saunders is personally signed by the artist.