At the recommendation of Archbishop Vsevolod (Maidansky) of Scopelos, and with the blessing of Patriarch Bartholomew of Constantinople, Roman Rudnyk then moved to Greece to continue his theological studies at the theological faculty of the Aristotlean University in Thessalonica, from which he graduated in 1997.
[2] In October 2002 he was sent to Portugal to serve at the newly created Saint Panteleimon parish in Porto.
[2] On March 21, 2004, was elevated to the rank of archimandrite by the Holy Synod of the Constantinopolitan Orthodox Church.
On January 11, 2005, the Holy Synod elected archimandrite Ilarion to the episcopacy as Bishop of Telmissos to serve as an auxiliary or assistant to the Greek Orthodox Metropolitan Epiphanius of Spain and Portugal.
On January 29, 2005, Bishop-elect Ilarion was consecrated to the episcopacy in the patriarchal Church of St. George in Constantinople.