When Aigio and the Northwestern Peloponnese tried to recover from the earthquake of 1817, the representative of Filiki Etaireia, Antonios Pelopidas, arrived in Patras from Constantinoupolis, aiming at the conversion of distinguished people of Achaia to the principles of the organization.
Among the results of that move was the Fight for Independence some years later, in 1821. The desire for freedom lay deep in the hearts of the people of Achaia and in Kalavryta, on 25 March 1821, they raised the Flag of the Revolution which was the start of the fight against the Turkish occupation.
The first meeting of the revolution took place at the beginning of February 1821 in Aigio without a positive outcome, while the first armed demonstration took place in Patras on 12th February.
The villages of Kalavritohoria, however, and the fighters N.Christodoulou or Soliotis, Andreas Petmezas, P.Fotilas, An.Giannopouloor Pantzos Pitsounas, An.Kerdis, G.Hondroyiannis, L.Pondiotis or Lambroulias and more, took the initiative attacked the conquerors at various places, such as in Agridi, Versova, Arfara, Helonospilia, etc. They also besieged the Turks at the castle of Kalavryta on 20th March, won the battle after 5 days and freed the area. The people of Patras followed their example and besieged the Turks in the castle on 23rd March, under the leadership of P.Anastasopoulos or Captain Karatzas.
This revolution expanded because of the "Achaic Directorate" that was set up with the initiative of metropolitan bishop Paleon Patron Germanos and of the proclamation that was given out to the consuls of the European powers on 26th March, in which the Greek people declared their desire to fight for their freedom.
Following the liberation of the country and the establishment of the Greek state, the people of Achaia excelled once again in the battlefields to free their land and their brothers from slavery. They also excelled in economy and politics, priding themselves on great politicians, 14 of whom became Prime Ministers of the country and two presidents.
Regarding the military sector, the 12thRegiment participated in all the battles of the nation, while in recent history (1940 - 1944) it suffered various blows from conquerors: On 28th October 1940, Italian invaders bombarded the civilians of Patras, causing numerous deaths and terror. On 13th December 1943, the german occupation army totally destroyed the city of Kalavryta and executed all males over 13. The Germans also proceeded
to group executions and destruction of the villages of Rogoi, Kerpini, Zachlorou, Vrahni, Souvardo, to executions of monks and the burning of the Monasteries of Agia Lavra and Megalo Spilaio.