A new Constitution was written in 1863. Extremely democratic, it envisaged a legislature with single room based on a representation proportional and elected by the male, secret and direct vote for all. The powers of the king were limited even.

Competition of parties

In spite of the presence of a new monarch and other constitutional provisions, the Greek political life remained unstable. After the Crimean War, the parties based on foreign bonds had been dissolved to make place with a system pluripartite centered on individual leaders. The elections were often corrupted and punctuated of acts of violence.  

After 1872, a bipartite system took form with the emergence of two principal leaders, Theodore Délighiannis and Charilaos Tricoupis. The Greek policy of the years 1870 to 1890 was dominated by the competition between these two men who defended of the antagonistic principles as regards foreign politics. Tricoupis estimated that the Greek government was to concentrate on the interior development and the social progress.

As of its come to power, it launched out an economic policy of modernization, supported by the installation in the country of Greek capitalists of the diaspora driven out by the rise of nationalisms; it continued the construction of the highway network and railway and the development of the banking system. On its side, Délighiannis was convinced of the need for continuing the Great Idea and for continuing to apply an active foreign politics.  

The expansionist policy

Even if the Greek State did not have the economic bases allowing him to follow an adventurous foreign politics, all the reign of Georges I er were placed under the topic of the territorial expansion. The areas under the Othoman yoke that coveted especially the Greek government were Thessalie, Epire, Macedonia and Crete.

To the XIX E century, Crete was the theater of successive revolts: in 1841,1858,1866-1868, 1878 and 1896-1897. After the insurrection of 1866, certain reforms were installation within the Cretan administration. In 1878, the protocol of Alep ratified the nomination of a Greek administration and the convocation of an assembly.  

The Cretan question had its importance, but the true problem in the Greek international relations was Macedonia. The Greeks installed in Crete represented prevalent nationality obviously. In Macedonia, the claims hellenists were thwarted by the Serb ones and the Bulgarian ones. In 1870, under the Russian pressure, the Othoman government instituted the exarchat, title of the chief of the Bulgarian national Church, which provided that if two thirds of a district Macedonian voted in favor of the exarchat, this emancipated entity of the oecumenical patriarchate of Constantinople would be placed under the supervision of the new Church. By the treaty of San Stefano (1878) which followed the Russo-Turkish war of 1877, Russia imposed the integration of a major part of Macedonia in the Bulgarian State.  

With the congress of Berlin, in 1878, Russia was forced to accept the dismemberment of Bulgaria in three parts and the return of Macedonia under the Othoman supervision. This space then became a major source of conflict between the three Neighboring states. Each one organized armed band and resistance networks in the form of cultural companies. For this period until our days, the problem of Macedonia has remained the leading cause of dissension between these three countries of the Balkan Peninsula.  

Following the decisions of the congress of Berlin, Greece made important acquisitions. In 1881, it annexed Thessalie and part of Epire. In 1878, the island of Cyprus, to Greek prevalence, was yielded to England by the Ottoman Empire. (This British possession was going to be at the origin of a major crisis after the Second world war).

In 1896, another rising occurred in Crete. The Greek government sent troops and ships to come to assistance of the insurrectionists. The great powers intervened once again to prevent the fastening of Crete in Greece, by imposing a blockade. In 1897, scuffles at the borders of continental Greece involved it in a war against Turkey. This conflict marked the superiority of the Turkish troops which inflicted a defeat with the Greek troops.  

The great powers prevented however the Ottoman Empire from benefitting from the situation. Greece lost only some pieces of territory along its borders and one required the payment of an allowance. The western powers imposed also the administrative autonomy of Crete. Prince Georges, son junior by Georges Ier, was named high commissioner of autonomous Crete. In 1906, following a disagreement with Cretan high officials, it was constrained to abdicate.  

In 1908, the revolution of the Young Turks of the Ottoman Empire called in question the statute of Crete and Macedonia. Once again, Crete sought the union with Greece. Under the pressure of the great powers, the Greek government was obliged to give up any attempt at union, to the dismay of the Greek public opinion. The military League, formed by a group of radical officers, was given to reform the government.

After having fomented successfully a coup d'etat in 1909, it called upon the councils of the Cretan politician Eleuthérios Vénizélos. As of its arrival in charge of the government, Vénizélos led the members of the military League to dissolution, then launched a constitutional reform. The revised Constitution in June 1911 made it possible to improve the effectiveness of the government. Vénizélos started negotiations with the close Balkan countries, whose failure leads to the release of the first war of Balkans.  

Economic problems

Georges I er was assassinated in Salonique in March 1913. His/her son, Constantin I er, succeeded to him. Interior economic development was not worthy of the projections as regards foreign policy carried out under the reign of Georges the Ist government made several loans as from 1830 abroad. The deterioration of public finances was such at the end of the XIX E century that the Agreement imposed at the Greek State the presence of an economic International commission of control.