It was recognized to be a community by the G.D 31-8-1912 after the pause of the operation and division of Lefktron Municipality. The Municipality appeared for the first time in the administrative history of newer Greece in 1835 after the G.D 9-3-1835. First it was put in the 3rd rank with population of 768 inhabitants and center the village of Pyrgos and following, by the G.D 21-11/1940 published in the newspaper of the government 5/1841 it was put in the 2nd rank with population 5729 inhabitants, the center being the village of Platsa. Administratively, it belonged to the county of Vytilo of Laconia Prefecture.
In 1840, when the big merge of the Municipalities took place at Lefktron Municipality they incorporated the villages of the annulled Municipalities Pefnos, Milea, Thalames, Poliana and Kastanea.
The official stamp of the Municipality was defined after the proposition of the archaeologist P. Efstratiadis with the G.D 3-11/1870 published in the newspaper of the government 4/1871. It was round whereas in the center it demonstrated “ a column on oak leaves and an arrow hanging from the column” (E. Skiadas – Ιστορικό Διάγραμμα των Δήμων της Ελλάδας 1833-1912).
First mayor was Ioannis Konstantopoulos who was replaced in 1940 by Constantinos Kyvelos who until then was the mayor of Milea.
In 1842, Jiannakis Petreas was appointed mayor. At the elections in 1944, bloody riots broke out in the municipality during affrays with the forces of Petrakis Kyriakoulis Mavromihalis. Jiannakis Petreas was replaced in 1846 by Pierros Kallagas who remained at the mayor’s place until 1850 when he was replaced by Ioannis Zaveas.
Amongst the mayors who offered a lot to Lefktron Municipality there were also: Stylianos Stylianeas who originated from Platsa and was elected in 1866, Xristos Xristeas who originated from Lefktron and was elected in 1870.
Lefktron Municipality ceased to be the Organization of the Local Selfgovernment and was divided administratively in small communities by the Law ΔΖΝ 71912 and became were taken from Laconia Prefecture to Messinia Prefecture in 1937 (Α.ν. 102β/24-12-3-1937, ΝG A8/1938)
The community was renamed to Karyovouni Community with the G.D17-7-1930. The community consisted of the villages Arahova and Piala. Then, the village Piala was renamed Dryopi by the G.D 18-5-1956, which was published in the newspaper of the government A 125/1956. In 1928, the village Arahova had 159 inhabitants and Piala 61. In 1940, the village Karyovouni had 173 inhabitants and Piala 81. In 1951, Karyovouni had 129 and Piala 57. In 1991, 84 and 7. In 2001, 71 and 11, respectively.