Constantine was born on August 27, 1780 in the then Ottoman occupied village of Tsaritsani of Thessaly, Greece. He received his early education from his father, Kyriakos Oikonomou, who was a priest and a scholar. He continued his studies at the the village of Ampelakia including learning French.
In 1806, Father Constantine was accused of having taken part in the rebellion of Father Efthymios Vlachavas. As a result, he was arrested and jailed in Ioannina. Subsequently freed, he took refuge in the Monastery of the Forerunner in Serres, in Greek Macedonia. Later, he moved to Thessalonica where he spent two years.
In 1809, Fr. Constantine became a father. He was also soon called to a position in Smyrna in Asia Minor to teach at the local "Gymnasium of Philology", of which he became head master. In 1819, he was called to Constantinople by Patriarch Gregory V, who named him Treasurer of the Patriarchate and "Preacher of the Grand Church of Christ".
Following the start of the Greek War of Independence and the martyrdom of Patr. Gregory, Fr. Constantine fled in 1821 to Odessa in Russia. On June 19, 1821 in Odessa, he participated, including delivering the eulogy, in the funeral of his former mentor, Patr. Gregory, who had been hanged in Constantinople on Pascha April 10, 1821.
Fr. Constantine remained in Russia until 1834 when he returned to a newly-independent nation of Greece. In the new environment of an independent Greece, Fr. Constantine, conservative in his thought, actively opposed foreign-inspired ideas and reforms of the Enlightenment, especially those of Fr. Theophilos Kairis and Adamantios Korais. In ecclesiastical issues, he opposed the translation of the Bible into modern Greek, then being proposed by Archimandrite Neophytus Vamvas, as well as the independence of the Church of Greece from the Church of Constantinople.