In 1917, Grigorescu was the commander of the Romanian armies in the Battle of Mărăşeşti, in which he achieved his greatest success, defeating German troops led by General August von Mackensen.
In 1917, during the Romanian Campaign, Grigorescu was the commander of the Romanian armies in the Battle of Mărăşeşti. It was there that he achieved his greatest success, managing to defeat Imperial German troops led by General August von Mackensen.