 He was the brother of Lazaros Kountouriotis, another ship-owner of the Greek War of Independence and grandfather of Pavlos Kountouriotis who fought in the First Balkan War and later served as first President of the Greek Republic.When the War of Independence broke out, Georgios, along with the rest of the Kountouriotis family, supported the effort with generous donations as well as with their ships.He was often at odds with other Hydriot sea captains, but ultimately was the wealthiest.