The Flessas family has existed in Greece's Peloponnisos since the 1600's from the time in which Venetians ruled the area. The name "Flessas" comes from the Bavarian word "Flosse" which means "raft". These "Flosserei" or lumbermen from Bavaria formed large wooden rafts and transported wood on rivers to pulp and papers mills.

Since one's occupation was often denoted by the last name, they were named "Flessa" and, later, "Flessas" in Greek. (There is a large Bavarian family named Flessa and the Flessa's have their own bank in Germany called the Flessa Bank). Bearers of the surname Flessas were found in Asia Minor as early 1100’s, Poliani Kalamata (Greece), and in Prussia where the name emerged from medieval times as one of the noteworthy families of the region.

From the thirteenth century onwards the name Flessas was identified with great social and economic movements and members of the Flessas family were major contributors in the rise and creation of the modern Greek nation. In Greece, Gregory "Papa" Flessas ("Papa" means "priest" in Greek) was a principal organizer and leader in the Greek revolution which began in 1821 and during which Greeks revolted against the rule of the Ottoman Turks. Papa Flessas sacrificed himself in the famous battle of Maniaki where the Turkish Army of 14,000 men killed him along with his 600 soldiers on May 20th, 1825.

Dimitrios George Flessas (1745-1799) was the patriarch of the Greek Flessas family. He married twice and had a total of twenty-eight children. With his first wife (Constantina Andronikou) he had eighteen children. After the death of his first wife, he and his second wife (Theodora Notara) had ten children.