 Complete the following phrase:  A seminal event occurred in 1821, when the rise of Greek nationalism in various parts of the Balkans in connection with the Greek War of Independence led to occupation of the two states by the Filiki Eteria, a Greek secret society who sought, and initially obtained, Russian approval. A mere takeover of the government in Moldavia, the Eterist expedition met a more complex situation in Wallachia, where a regency of high boyars attempted to have the anti-Ottoman Greek nationalists confirm both their rule and the rejection of Phanariote institutions. A compromise was achieved through their common support for Tudor Vladimirescu, an Oltenian pandur leader who had already instigated an 