He was a political personality famous for his work towards national progress, his patriotism and unselfishness, despite his having been in office during a very unsettled period of Greek history.
After the Greek War of Independence, he moved to Nafplion where he went to school, then to Athens to study law.
In 1841, he took part in the revolution in Crete despite believing it was a lost cause—the conditions were not right for such an undertaking at that time.
Koumoundouros’ long career encompassed many facets of political life, including serving in parliament, authoring of legislation, promotion of a democratic regime, restoration of the army, distribution of national farms to landless farmers, and the approval of major construction work (such as the Isthmus of Corinth).
During his 50-year-long period of political involvement he tried to remain neutral, and to avoid confrontation both with the three Great Powers and with the smaller powers of that time. In this period he held various ministerial appointments eighteen times, was twice president of the Greek Parliament and ten times Prime Minister of Greece. Despite often experiencing inimical conditions, including at least three assassination attempts, he still managed to create a firm foundation for democracy in Greece.
Meanwhile, he was appointed as Public Prosecutor in the Tribunal of Kalamata, but he soon quit this position in order to become a politician. His first political distinction emerged in 1853 when he was elected deputy of the province of Messinia (the province of Kalamàta). Two years later he became President of the Greek Parliament, and the following year Minister of Economics.
He kept the same ministry in the new governments both of 1857 and 1859. After the overthrow of King Othon in 1862 he became Minister of Justice of the temporary government.
The first elections for a proper government after the fall of King Othon took place in 1863 and Koumoundouros remained as Minister of Justice, however, the extremely poor political stability lead to new elections the following year.
In the succeeding government of 1864, Koumoundouros was moved to the Ministry of Religion and Education and later to the Ministry of Internal Affairs.
On March 25, 1865, he became Prime Minister of Greece for the first time and won the elections of 1866, too. Four years later, he retained the position of the Minister of Army and Internal Affairs, in addition to being Prime Minister. In 1875, Koumoundouros was successful in uniting all other parliamentary parties against Charilaos Trikoupis. In August 1875, he became President of the Parliament once again and in the elections of the same year he was made Prime Minister of the country once more.
Elections took place three times in 1876 and Koumoundouros was victorious in two of them. He also won the elections of 1878.
The time of Koumoundouros’ greatest achievement came in 1881 during his last (tenth) premiership, after diplomatic contacts with Turkey, he managed to bring about the annexation of areas Thessaly and Arta to the Greek mainland.
Right after this achievement he called for new elections so that representatives of the newly annexed regions could enter Parliament. Despite this concession, the new candidates elected the representative of the opposition party as President of Parliament. As a result, Koumoundouros resigned on March 3, 1882. He died some months later on February 26, 1883, in his home on Ludwig Square (now known as Koumoundourou Square), in Athens, and was buried at public expense in the First Cemetery of Athens.
After the end of the unsuccessful Cretan revolution, he married Ekaterìni Konstantinou G. Mavromichàli of the famed Maniot family. They had two children. His first son Konstantìnos, was born in Kalamata 1846, and daughter Marìa, was born in Kalamata 1845. Ekaterìni died young and Koumoundouros married Efthimìa Perotì who presented him with his second son in 1858, Spirìdonas and in 1867 a daughter, Olga.Other spellings of his name are: Kumunduros and Komunduros
. Consult Bikélas, Coumoundouros
, (Montpelier, 1884).