Nathanael was born in 1978 in Thessaloniki to Irene and Vasilios Symeonides. In 2003 he graduated from Hellenic College and became a deacon, and in 2010 he was ordained as a priest. In 2016 he served as the director of the Office of Inter-Orthodox for the Interfaith Relations at the Greek Orthodox Archdiocese of America in collaboration with the
Council on Foreign Relations. He was elected Metropolitan of Chicago in February 7, 2018, and was ordained a bishop on March 17, 2018 and enthroned March 24, 2018. On September 7, 2024, two days before the one year anniversary of the opening of
Chicago's first casino, Nathanael denounced legalized gambling, stating it "disrupts our brain, [and] degrades our dignity". ==References==