Probably more than a quarter of Romania's farmland was controlled by untaxed Eastern Orthodox "Dedicated Monasteries", which supported Greek and other foreign monks in shrines such as Mount Athos and Jerusalem. These estates, which were mostly formed under Phanariote reigns in Wallachia and Moldavia respectively, had a low productivity and were also a substantial drain on state revenues.
In August 1863, Cuza offered compensation to the Greek Orthodox Church, but Sophronius III, the Patriarch of Constantinople, refused to negotiate; after several years, the Romanian government withdrew its offer and no compensation was ever paid. State revenues thereby increased without adding any domestic tax burden.
References
Keith Hitchins, The Romanians, 1774-1866, pp. 313-314. Oxford University Press, USA (1996). ISBN 0198205910