 At the beginning of the Greek War of Independence, when the Eteria began its expedition in Moldavia and Wallachia, Olympios was appointed leader of the Greek forces in Bucharest by Alexander Ypsilantis, at first cooperating with Tudor Vladimirescu, who led the parallel Wallachian uprising.However, when Vladimirescu distanced himself from the Fililiki Eteria, Olympios was responsible for his arrest on 1 June in Goleşti - following which Vladimirescu was summarily put to death .He took part in the Battle of Sculeni on 29 June 1821, when Ottoman forces chased him (along with Yiannis Pharmakis and a small force of 400 Greeks) to the Secu Monastery in the Neamț County, where the Greeks made their last stand.