He was born in Gastouni in Elis, to a rich and historic family of the area. Georgios, his father Chrysanthos and his three brothers, who died young, were all physicians. During the Ottoman rule, he was a primate (prokritos) of Gastouni.
He became a member of the Filiki Eteria in 1819. In 1821, as the Ottoman authorities suspected the Greeks of planning a revolution, he was requested to come to Tripolitsa along with other primates; at the suggestion of Germanos of Old Patras, he feigned illness and did not attend. Sisinis proclaimed the start of the Greek War of Independence in Elis, and was one of the most important contributors to the Greek struggle. He provided the Greek troops in the Peloponnese with provisions, and distinguished himself in the battles of Patras, Lala and of Chlemoutsi.
Under Governor Ioannis Kapodistrias, he was appointed a member of the Panellinion, and in 1829 he was named president of its successor, the Senate. He resigned following disagreements with Kapodistrias, but was not involved in the Governor's assassination in 1831, which he condemned.
He married Yakinthi Stathakopoulou and had two sons, Michail and Chrysanthos.
He died at Gastouni in 1831.
His descendants include the writer David Patrikarakos.[1]
