The Hellenic Navy (HN; , abbreviated ΠΝ) is the naval force of Greece and one of three branches of the Hellenic Armed Forces where they use the prefix HS (Hellenic ship).

The modern Greek navy historically hails from the naval forces of various Aegean Islands that fought in the Greek War of Independence. During the monarchic period (1833–1924 and 1936–1973), it was known as the Royal Hellenic Navy (, , abbreviated ΒΝ).

The Hellenic Navy is a green-water navy. The total displacement of the fleet is approximately 150,000 tons. The HN also operates a number of naval aviation units.

The motto of the Hellenic Navy roughly translates to "Great is the nation that controls the sea",Μέγα τὸ τῆς θαλάσσης κράτος from Thucydides' account of Pericles' oration on the eve of the Peloponnesian War. At the Perseus Project.Thucydides, History of the Peloponnesian War, 1.143. The Hellenic Navy's emblem consists of an anchor in front of a crossed Christian cross and trident, with the cross symbolizing Greek Orthodoxy, and the trident symbolizing Poseidon, the god of the sea in Greek mythology. The motto is written across the top of the emblem.

History

The history of the Hellenic Navy begins with the birth of modern Greece, and due to the maritime nature of the country, it has always featured prominently in modern Greece's military history.

The Navy during the Revolution (1821–1830)

At the beginning of the Greek War of Independence, the naval forces of the Greeks consisted primarily of the merchant fleet of the Saronic islanders from Hydra, Spetsai and Poros and also the islanders of Psara and Samos. The fleet was of crucial importance to the success of the revolution. Its goal was to prevent as much as possible the Ottoman Navy from resupplying the isolated Ottoman garrisons and land reinforcements from the Ottoman Empire's Asian provinces.

Although Greek crews were experienced seamen, the light Greek ships, mostly armed merchantmen, were unable to stand up to the large Ottoman ships of the line in direct combat. So the Greeks conducted the equivalent of modern-day naval special operations, resorting to the use of fireships ( or ), with great success. It was in the use of such ships that courageous seamen like Konstantinos Kanaris won international renown. Under the leadership of capable admirals, most prominently Andreas Miaoulis from Hydra, the Greek fleet achieved early victories, guaranteeing the survival of the revolution in the mainland.

However, as Greeks became embroiled in civil wars, the Sultan called upon his strongest subject, Muhammad Ali of Egypt, for aid. Plagued by internal strife and financial difficulties in keeping the fleet in constant readiness, the Greeks failed to prevent the capture and destruction of Kasos and Psara in 1824, or the landing of the Egyptian army at Modon. Despite victories at Samos and Gerontas, the Revolution was threatened with collapse until the intervention of the Great Powers in the Battle of Navarino in 1827. There the Egypto-Ottoman fleet was decisively defeated by the combined fleets of the Britain, France and the Russian Empire, effectively securing the independence of Greece.

When Ioannis Capodistrias became governor of newly liberated Greece in 1828, the Greek fleet consisted of few remaining ships, which had participated in the war for independence. The first minister of "Naval affairs" was Konstantinos Kanaris, and the most powerful ship of the fleet at that time, the frigate Hellas, had been constructed in the United States in 1825. The Hellenic Navy established its headquarters at the island of Poros and the building of a new series of ships began at the naval base, while old ships were gradually being retired. Furthermore, continuous efforts towards the education of officers were initiated. Young people were initially trained at the military school of Scholi Evelpidon and afterwards they were transferred to the navy, as there was no such thing as a Naval Academy.Official website of the Hellenic Navy .

In 1831, Greece descended into anarchy with numerous areas, including Mani and Hydra, in revolt. It was during this revolt that the flagship Hellas, docked at Poros, was set on fire by Admiral Andreas Miaoulis.Politics and Statecraft in the Kingdom of Greece, John Anthony Petropulos, Princeton University Press, 1968. Capodistrias was assassinated a few months after.

The Royal Hellenic Navy of King Otto (1830–1860)

When the new King Otto arrived in the Greek capital, Nafplion, in 1832 aboard the British warship HMS Madagascar, the Greek fleet consisted of one corvette, three brigs, six schooners, two gunboats, two steamboats and a few more small vessels. The first naval school was founded in 1846 on the corvette Loudovikos and Leonidas Palaskas was assigned as its director. However, the inefficient training of the officers, coupled with conflict between those who pursued modernization and those who were stalwarts of the traditions of the veterans of the struggle for independence, resulted in a restricted and inefficient navy, which was limited to policing the sea and the pursuit of pirates.

During the 1850s, the more progressive elements of the navy won out and the fleet was augmented with more ships. In 1855, the first iron propeller-driven ships were ordered from England. These were the steamships , Pliksavra, , and Sfendoni.

Growth of the Navy under King George (1860–1910)

On October 29, 1863, following an enthronement ceremony in his native Copenhagen and a tour of several of the European capitals, Prince Wilhelm of Denmark arrived aboard the Greek flagship Hellas, to take up the throne as King George I of Greece. During the 1866 Cretan revolt, the Royal Hellenic Navy ships were in no condition to support it. Such failure led to the government awakening to the problem of naval insufficiency and the adoption of a policy stating that: "The navy, as it represents a necessary weapon for Greece, should only be created for war and aim to victory." Because of this, the fleet was supplied with new and bigger ships, reflecting a number of innovations including the use of iron in shipbuilding industry and the invention of the torpedo; with these advances, the effectiveness and the appearance of the Hellenic Navy changed.

Meanwhile, after 1878, because of the Russo-Turkish War and the need to expand the Greek navy, a new and larger naval base was established in the area of Faneromeni of Salamis and a few years later it was transferred to the area of Arapis where it remains today. At the same time the Naval Academy was founded and Ilias Kanellopoulos was made Director. A French naval mission, headed by Admiral , introduced a new, advanced naval organization and the methodological training of enlisted personnel through the establishment of a training school in the old building of the naval base in Poros. During the government of Charilaos Trikoupis in 1889, the fleet was further increased with the acquisition of new battleships: Hydra, Spetsai, and Psara from France. Thus, when Greece went to war in the Greco-Turkish War in 1897, the Hellenic Navy established its dominance in the Aegean Sea. However, it was unable to change the outcome of the war on land, which was a national humiliation.

In 1907, the Hellenic Navy General Staff () was founded, with then-Captain Pavlos Kountouriotis as its first head. After the war, in 1897, the Ottoman Empire embarked on a program of naval expansion for its fleet and as a response to that, in 1909, the cruiser Georgios Averof was bought from Italy. In 1910, a British naval mission arrived, headed by Admiral Lionel Grant Tufnell, in order to recommend improvements in the organization and training of the navy. The mission led to the adoption of the British style of management, organization and training, especially in the area of strategy.

Balkan Wars (1912–1913)

Shortly before the Balkan Wars, the Navy was composed of a fleet of destroyers and battleships. Its mission was primarily offensive, aiming to capture the Ottoman-held islands of the Eastern Aegean and establish naval supremacy. To that end, its commander-in-chief, Rear Admiral Pavlos Kountouriotis, established a forward base at the Moudros bay at Lemnos, directly opposite the Dardanelles straits. After defeating the two Turkish sallies from the Straits at Elli (December 1912) and Lemnos (January 1913), the Aegean Sea was secured for Greece.

The Balkan Wars were followed by a rapid escalation in 1914 between Greece and the Ottoman Empire over the status of the islands of the eastern Aegean. Both governments embarked on a naval armaments race, with Greece purchasing the battleships and and the light cruiser as well as ordering two dreadnoughts, and and a number of destroyers. However, with the outbreak of the First World War, construction of the dreadnoughts stopped.

World War I and aftermath (1914–1935)

Initially during the war, Greece followed a course of neutrality, with the Prime Minister Eleftherios Venizelos favouring the Entente and pro-German King Constantine I advocating neutrality. This dispute eventually led to a deep political conflict, known as the "National Schism". In November 1916, in order to apply pressure on the royal government in Athens, the French confiscated the Greek ships. They continued to operate with French crews, primarily in convoy escort and patrol duties in the Aegean, until Greece entered the war on the side of the Allies in June 1917, at which point they were returned to Greece. Subsequently, the Navy took part in the Allied operations in the Aegean, in the Allied expedition in support of Denikin's White Armies in Ukraine, and in limited operations during the Greco-Turkish War of 1919–1922 in Asia Minor.

After Greece's defeat, the 1920s and early 1930s were a politically turbulent period, with the economy in a bad state, so the Navy received no new units, apart from the modernization of four destroyers and the acquisition of six French submarines in 1927 and four Italian destroyers in 1929.

World War II (1939–1945)

In 1938, Greece ordered four modern Greyhound-class destroyers in British shipyards, making a serious step towards modernization. The outbreak of war in Europe, however, allowed only two to be delivered. Greece entered World War II with a navy consisting of two battleships, one armoured cruiser, one protected cruiser, fourteen destroyers, and six submarines.

During the Greco-Italian War, the Navy took over convoy escort missions in the Ionian Sea and even embarked on three raids against the Italian supply convoys in the Strait of Otranto, although without success. The most important role was given to the submarines, which although obsolete, sank some Italian cargo ships in the Adriatic, losing one submarine in the process. The Greek submarine force (six boats) was however too small to be able to seriously hinder the supply lines between Italy and Albania (between 28 October 1940 and 30 April 1941, Italian ships made 3,305 voyages across the Otranto straits, carrying 487,089 military personnel, including 22 field divisions, and 584,392 tons of supplies while losing overall only seven merchant ships and one escort ship).Pier Filippo Lupinacci, Vittorio Emanuele Tognelli, La difesa del traffico con l'Albania, la Grecia e l'Egeo, Ufficio Storico della Marina Militare, Rome 1965, pp. 47–49.

When Nazi Germany attacked Greece, the RHN suffered heavily at the hands of the Luftwaffe, with 25 ships, including the old battleship, now artillery training ship, Kilkis and the hulk of her sister Lemnos, lost within a few days in April 1941. It was then decided to shift the remaining fleet (one cruiser – the famous – three destroyers and five submarines) to join up with the British Mediterranean Fleet at Alexandria.