He was born in Constantinople on the 9th of December 1867. His father, Dionysios, was born in Zante and his mother Efthalia in Constantinople. Gregorios spent his childhood and adolescence in Zante till 1883, when he entered the University of Athens to study physics and Mathematics. He never completed his studies. He quit University during the 1st yearof his studies; literature became a big part of his life, also being his only means of supporting himself.
Xenopoulos made his literary debut when he was a fifteen year old high school pupil, with his unwieldy novel “the Devil’s Wonders”. This novel was never published. It was rejected by the publishers, as they claimed was written by an amateur. A year later, in 1883 he went to Athens to study physics and mathematics. At the time the respected literary Greek magazine ‘Estia’, declared for a second year in a row a competition for the best short story. Xenopoulos participated in the competition with a satiric short novel about the results of the competition of the previous year! He did not win the competition but he won praise by the referees who characterized him as a brilliant and an experienced writer! This young, inexperienced writer has already made an immediate impact in the literary world of Athens.
Since 1892 he lived permanently in Athens and in 1894 he married Efrosini Diogenidi. The couple divorced a year and a half later, while having a daughter, Leonia. It is evident that his divorce greatly influenced his psychology, especially at a time when it was not that common for couple to take divorce. Because of his divorce Xenopoulos was obliged by his former father in law to sign a ‘statement’ denouncing his daughter, even if therre was a provision for him to see her whenever he wanted. The writer remarried in 1901 to Christina Kanellopoulou with whom he had two more daughters.
He collaborated with many newspapers and magazines in which he published many studies, articles, short stories and novels.
In 1894 he took over the management of “Ikonografimeni Estia”. In 1896 he was chief editor of the magazine “Diaplasis ton Paidon” and from 1901 till 1912 he published his novels and studies in the “Panathiniaa” magazine. From 1912 he started cooperating with the newspaper “Ethnos” writing short stories in sequels. In 1927 until 1934 he founded and was the director of the Magazine “New Estia”.
In 1944 his house in Athens was completely destroyed by a fire. The fire destryed completely his archive including two librettos for operettas that unfortunately were never found since.
He died in Athens on the 14th of January 1951 and his funeral was at public expense.