Greece can be easily ignored by many monarchists today because the ruling regime is so hostile to the former royal family and the royals so increasingly removed from the country that it can seem like a lost cause more along the lines of the plight of the Dalai Lama than even the King of Romania in terms of the liklihood of the success of a restoration. However, the Greek monarchists deserve a great deal of credit for fighting the good fight far more frequently and for greater durations than most other monarchists, especially in modern times. It is also important to note that when modern Greece won its independence from the Turks in 1829 it originally went back to the classical period which is so idealized and founded a republic. Monarchists should be quick to point out that this republic did not last long because it proved totally incapable and so a monarchy was established, first under King Othon, formerly Prince Otto of Bavaria (hence the Wittelsbach colors of blue and white in the Greek flag). He was eventually overthrown and is often upheld as an example of royal failure, but given the situation on the ground in Greece the fact that he reigned for 30 years is not an accomplishment to be totally dismissed.
King Alexander's death in 1920 brought his father Constantine back to the throne, but republican opposition; which blamed a loss of territory in the war with the Turks just after World War I on the King, unfair as it may be, meant that he abdicated again in favor of King George II in 1922. Liberal revolutionaries continued to plague the country and in 1924 they succeeded in overthrowing George II and establishing a very unstable and often dictatorial republican government. Poverty gripped the country and as usual this was used as an opening for the communists who began to infiltrate. The monarchists continued to struggle against them and for the return of the King which was finally achieved after a coup and referendum in 1935 which restored George II to the throne. Unfortunately World War II soon forced him to leave the country again and not only were Greeks forced to fight the Germans and Italians but also each other and with Soviet aid pouring in it was the communists who gained the upper hand in the on-going guerilla war.
Even before the war ended Great Britain and the United States were sending help to the Greek royalists for fear of Soviet expansion into Greece. Following the end of World War II open civil war erupted between the Greek communists and royalists with the USA backing the royalists and the USSR backing the communists. By 1949, thankfully, the royal government had managed to take control of most of the country. By this time George II was long gone as was the short reign of his brother Paul and in 1964 King Constantine II came to the throne. He inherited the problem of a country which failed to recognize the inherent dangers of liberal revolutionary thought even if not being preached by open and avowed communists. Thus, the Greek monarchy continued to be undermined particularly under the socialist regime of George Papandreou.
Despite his difficulties with Papandreou, King Constantine II did not favor the coup against him by the military and his efforts to restore some normalcy to the situation in Greece earned him nothing but his overthrow by the clique of colonels in 1973. After the fact they did hold a vote on the subject of the monarchy but it was highly suspect and, even if it had not been tampered with, it could hardly have been considered fair given the amount of totally unjustified blame that had been heaped on the monarchy by almost every previous administration. King Constantine II has been harshly criticized in many quarters since but it is hard for any reasonable, thinking person to understand why. He was not always successful, obviously, but he clearly was consistent in always trying to do the right thing for his people and his country. He was blamed for the military coup and yet this flies in the face of the fact that the military deposed him because he was planning a coup to end their dictatorship. The result was exile and hostility against the King ever since.
King Constantine II has lived in exile ever since, correctly still treated as a reigning monarch by Queen Elizabeth II and his other royal relatives and he has had to endure a continued stand-off with one of the most anti-monarchy regimes in Europe. Unfortunately, in my opinion at least, while he still calls himself "King Constantine" he leaves it at that and has recognized the republic and has made no effort to organize Greek monarchists to push for a restoration. It is, perhaps, understandable, but certainly a far cry from the grit and determination shown by Greek monarchists in previous generations.