Directed by the naturalist and geographer Jean-Baptiste Bory de Saint-Vincent, nineteen scientists representing different specialties in natural history, archaeology and architecture-sculpture made the voyage to Greece in March 1829; most of them stayed there for nine months.

Their work proved essential to the ongoing development of the new Greek State and, more broadly, marked a major milestone in the modern history of archaeology, cartography and natural sciences, as well as in the study of Greece.

[4] Many artists and intellectuals such as François-René de Chateaubriand,[7] Victor Hugo,[8] Alexander Pushkin, Gioachino Rossini, Hector Berlioz[9] or Eugène Delacroix (in his paintings of The Massacre at Chios in 1824, and of Greece on the Ruins of Missolonghi in 1826), amplified the current of sympathy for the Greek cause in the public opinion.

A plan to send a naval expedition as a demonstration of force was proposed and adopted; subsequently a joint Russian, French and British fleet was sent to exert diplomatic pressure against Constantinople.

At their arrival on the Greek soil, the French found a country that had just been ravaged by Ibrahim's troops: villages razed to the ground, agricultural crops entirely burned and a population still living under a yoke of terror, starving and secluded in caves.

In the middle of a few wooden huts built on the shore, outside the city (Navarino), of which only ruins remained, circulated, hasty and ragged, men, women, children, who had nothing left human in features: some without noses, others without ears, all more or less covered with scars; but what moved us at the last point was a little child of four or five years old whom his brother led by the hand; I approached him: his eyes had been gouged out.

[24][37] On 7 October, the 35th Line Infantry Regiment, commanded by General Antoine-Simon Durrieu, accompanied by artillery and by military engineers, appeared before Methoni, a better fortified city defended by 1,078 men and a hundred cannon, and which had food supplies for six months.

Because the Porte persisted in refusing to participate in conferences, General Maison explicitly suggested Greek Governor Ioannis Kapodistrias (on 5 October) pursuing military operations and extending them to Attica and Euboea.

[22] Only a single brigade, so-called "of occupation", of 5,000 men (composed of the 27th, 42nd, 54th and 58th Line Infantry Regiments stationed in Navarino, Methoni and Patras) remained in the Peloponnese under the command of General Virgile Schneider.

[50] The military engineering commander of the Morea expedition, Lieutenant-Colonel Joseph-Victor Audoy, was commissioned by the Governor of Greece Ioannis Kapodistrias to design the first urban framework plan of the country's modern history.

The example of the rapid modernization of Patras, whose plans had just been drawn by the Captains of the French expedition Stamatis Voulgaris and Auguste-Théodore Garnot, is described at length in the Souvenirs of Jacques Mangeart,[23] who came to the city with the Philhellene and Lieutenant-Colonel Maxime Raybaud to establish a printing company and found the Franco-Greek newspaper "Le Courrier d'Orient" in 1829.

[34] Thus, almost a third of French troops were affected by fevers, diarrhea and dysentery, which had been mostly contracted between October and December 1828 in the camps established within the marshy plains of Petalidi, in the mouth of the river Djalova (in Navarino Bay) or in Patras.

[66] The doctors attributed the disease mainly to the proximity of the focal point of infection in lowlands and marshy places and to the harshness of the transitions in temperatures between day and night, and to a lesser extent, to the intensity of the multiple and arduous works, as well as in the excessive consumption of salted meat, of spirits, and of the muddy and brackish water of the region.

[24][34] The cooler weather of winter, the moving of the men into the fortresses's barracks, the immediate enforcement of strict hygiene and sanitation measures, the arrival of drugs from France, as well as the establishment of three military hospitals in Navarino, Methoni and Patras significantly reduced this loss of life.

Since Greece was the other important region of antiquity considered the origin of Western civilisation (one of the philhellenes' principal arguments), it was decided, as mentioned by Abel Blouet,[72] to: ...take advantage of the presence of our soldiers who were occupying Morea to send a scholarly commission.

The Interior minister of King Charles X, the power behind the throne and real head of the government at the time, the Viscount of Martignac, charged six academicians of the Institut de France (Académie des Sciences: Georges Cuvier and Étienne Geoffroy Saint-Hilaire.

[78] A great dinner was organised at Modon, which brought together for the last time before the expeditionary force returned to France: President Kapodistrias, Marshal Maison, the Greek and French officers and principal chiefs (Kolokotronis, Nikitaras, Makriyannis, Kallergis, Fabvier, etc.

[84] However, after the departure of the scientific mission from Greece, and although he fell ill with fever five times, Peytier remained there alone until 31 July 1831 to complete the trigonometric, topographic and statistical work for the establishment of the map of the Morea.

The French geographer and Greek specialist, Michel Sivignion indicates that the map depicts, for the first time, an exact rendering of the topography, of the layout of the rivers, of the height of the mountains, and also of the distribution of inhabited places and of the size of their populations.

[85] The Governor of Greece Ioannis Kapodistrias also commissioned Pierre Théodore Virlet d'Aoust to assess the possibility of digging a canal on the isthmus of Corinth,[60] to save ships the 700 kilometres (430 mi) journey around the Peloponnese and the dangerous pass of the capes Maleas and Matapan (Tainaron) south of the peninsula.

[89] Similarly, the well-known naturalists Étienne and his son Isidore Geoffroy Saint-Hilaire helped him to write and edit the expedition's scientific works, under the supervision of Georges Cuvier at the institute.

[73] This section, supervised at the Académie des Inscriptions et Belles-lettres by Charles-Benoît Hase and Desiré-Raoul Rochette, was composed of the archaeologists Léon-Jean-Joseph Dubois (director) and Charles Lenormant (assistant-director), by the historian Edgar Quinet and by the painters Eugène-Emmanuel Amaury-Duval and Pierre Félix Trézel.

Charles Lenormant, for instance, when he learned that he was under the orders of Dubois, or at least that he was going to go along with him, did not think he should accept this position with a man who was his subordinate at the Louvre (he was just returning from the Egyptian archaeological expedition organised by Jean-François Champollion in 1828); consequently he made the trip as an amateur and alone.

Possessed of a wide-ranging experience formed in Italy, Greece, Egypt and the Middle East, and under the influence of engineers, he asked them to keep an authentic diary of their excavations where precise measurements read off watches and compasses should be written down, to draw a map of the region they travelled, and to describe the layout of the terrain.

The presence of the troops from the expeditionary corps was important, alternating with that of the Greek shepherds: "[...] their generous hospitality and simple and innocent manners reminded us of the beautiful period of pastoral life which fiction calls the Golden age, and which seemed to offer the real characters of the Theocritus' and Virgil's eclogues.

"[103] Having explored Navarino, Methoni and Koroni, the members of the section went to the ancient city of Messene (founded in 369 BC by the Theban general Epaminondas after his victory over Sparta at Leuctra), located on the slopes of Mounts Ithome and Eva.

These excavations, carried out by means of dug trenches, enabled them to determine the precise plans of the foundations of the monuments and thus to propose restored models of the stadium of Messene and its heroon, as well as the small theater or ekklesiasterion.

Only the Clepsydra fountain (where according to Pausanias, Zeus as a child was washed by the nymphs Ithome and Neda), located higher in the village of Mavrommati, was described and drawn.Then, the expedition spent six weeks, starting on May 10, 1829, in Olympia.

Blouet refused to perform excavations that risked damaging the monuments, and banned the mutilation of statues with the intent of taking a piece separated from the rest without regard, as Elgin had done on the Parthenon some twenty-five years before.

"[116] As for the physical sciences section, its members had forgotten to install mosquito nets in their tents before exploring the mouth of the Eurotas in July 1829, and subsequently they were bitten by a species of mosquito that Gaspard Auguste Brullé was the first to describe scientifically as the Culex kounoupi Br., Pierre Théodore Virlet d'Aoust, Sextius Delaunay, Prosper Baccuet, Gaspard Auguste Brullé, three muleteers, two sappers, an interpreter and the valet Villars, were all seized with violent fevers, which sometimes worsened to the point of delirium, and which precipitated the departure of the section for Malvoisie, thus suspending their works.