'Mars I' was the Axis movement of Romanian reinforcements for General de corp de armatâ Petre Dumitrescu’s Romanian 3^rd Army and General de corp de armatâ Nicolae Ciupercă's Romanian 4^th Army committed to the Axis 'Blau II' summer offensive of 1942 within Generalfeldmarschall Fedor von Bock’s Heeresgruppe 'Süd' (later Generalfeldmarschall Maximilian Reichsfreiherr von Weichs’s Heeresgruppe 'B') on the Eastern Front (spring 1942).