The rise of Wallachian clienteles was again curbed in 1821 by an anti-boyar uprising, under Tudor Vladimirescu; having a peasant base, this insurgency was probably led by disgruntled third-class boyars. Also in 1821, the Phanariote warlord Alexander Ypsilantis, leading a "Sacred Band" of Greek revolutionaries, had taken control over Moldavia and parts of Wallachia. Ypsilantis' expedition sparked another Ottoman intervention, which provided a settling of scores between Romanians and Greeks. Second-class boyars played significant parts: according to Eliade, a "Spatharios" and a "Paharnic" traveled from one Moldavian town to another, replacing Ypsilantis' men with friendly locals. The "Paharnic" Gavril Istrati was involved alongside Sturdza in the fight against Sacred Band Greeks, at the head of a national party. At Zvoriștea, he organized a guerrilla force which flew red flags. It then marched on Botoșani, driving out the Greek insurgents.