Zygouris was the third son of Lambros and Moscho Tzavelas. He was born in Souli and, after its fall to the forces of Ali Pasha, followed his brother Fotos to Corfu. There, he joined the Russian army as an officer.
In 1820, he returned to the mainland to fight alongside Ali Pasha against the Turkish forces of Hursid Pasha. When Ali Pasha's rebellion failed, Tzavelas made his way south to Rumeli and fought in the Greek War of Independence which broke out on March 25, 1821.