Polychronis Lembesis was born on 18 December 1848 on the island of Salmina, located near Athens. As a little boy, he spent much time in the monastery of Faneromeni, painting Byzantine icons.
He initially studied at the Athens School of Fine Arts and, in 1875, continued his studies at the Royal Academy of Fine Arts Munich. At the academy, he studied with Wilhelm Lindenscmidt and Ludwig von Lofftz. While in Munich, he became friends with fellow Greek painter Nicholaos Gysis.
In 1880, Lembesis returned to Athens. Although he was a master in Landscape Painting, he is better known for his portraits.
He died in 1913 poor and unknown as an artist, due to a shift in Athenian artistic taste from the Munich School to more modern art movements happening in Paris. Today Lembesis is considered one of the most important representatives of the Munich School art movement.