Although Bodrum is known mainly as a holiday destination, which attracts crowds of people looking for discos, beaches, and fun during the summer months, lovers of history and architecture will also find many attractions in this city. The greatest tourist and sightseeing experience that you can have during your stay in Bodrum is a visit to the fortress towering over the port. This huge structure is the Castle of St. Peter, and its interiors contain treasures found under the waters of the Mediterranean Sea by archaeologists and sponge divers.

Construction of the castle

At the beginning of the 15th century, in the face of the threat of Turkish invasion, the Hospitaller Order, whose headquarters were on the island of Rhodes, decided to build a fortress on the mainland. The location was chosen by the Grand Master of the Order, Philibert de Naillac. He decided that the castle would be constructed on the site of the ancient city of Halicarnassus, opposite the island of Kos, where the fortress belonging to the Order also stood. The chosen site had long been known as strategically important, and the earliest fortifications known to researchers in this location date back to the Doric period (around 1100 BCE). Previously, in the 11th century CE, a small castle had been built on the same promontory by the Seljuks, and scholars suspect that the palace of the famous Mausolus, ruler of Caria in the 4th century BCE, had previously stood there.

The construction of the Hospitaller fortress began in 1404, under the direction of the German knight and architect Heinrich Schlegelholt. A papal decree from 1409 guaranteed the builders working on the construction a place in heaven. Volcanic stones and remains from the nearby Mausoleum, a former Wonder of the Ancient World, were used to construct the fortress walls. Marble columns and reliefs, taken from this once magnificent building, are visible in the castle walls.

The most modern architectural solutions of the time were used when designing the fortress. The passages leading to the entrance gates twisted and turned so that the invaders could not take shelter from the hail of arrows, stones, and other heavy objects dropped on their heads from the fortifications.

The first round of work was finished in 1437. One of the earliest structures completed on the fortress grounds was a chapel, dating to 1406. It consisted of a vaulted nave and an apse. The chapel was rebuilt in 1519-1520 by Spanish knights, giving it Gothic features. Fourteen cisterns were carved out of the rock beneath the castle to collect rainwater. This was to provide a supply of drinking water in the event of a prolonged siege of the fortress. The castle was given the name of St. Peter, and the entire town around the fortifications was known as Petronium from then on.

Since the Order of Saint John included knights of various origins, speaking many languages, each group was given one defensive tower. Each such language group was responsible for maintaining and defending a designated section of the walls by equipping an appropriate number of armed men. There were seven gates to the inner fortress. Above the gates and on the walls themselves, the knights placed hundreds of coats of arms and carved reliefs, of which 249 patterns have survived to this day. They represent the coats of arms of the Grand Masters of the Order, the commanders of the castle, individual countries, and knights and clergy.

The construction of St. Peter's Castle was completed by the Grand Master of the Order of Saint John, Pierre d'Aubusson, between 1476 and 1503. For over a hundred years from the beginning of the construction of the fortress until its handover to the Ottoman troops, the fortress was the second most important castle of the Order of Saint John and served as a refuge for Christians from Asia Minor.

In the years 1505-1507, the fortress was decorated with bas-reliefs obtained from the ruins of the Mausoleum of Halicarnassus. Among the decorations used, it is worth mentioning twelve panels depicting the Amazonomachy, or the battle with the Amazons, and one scene from the Centrauromachy.

Characteristics of the fortress

St. Peter's Castle is located on a promontory jutting out into the sea. It has a square-like plan (180 by 185 meters) and covers an area of around ​​33,000 square meters. At its highest point, the fortress rises 47.5 meters above the waters of the Aegean Sea. On the north and west sides, the defensive walls are double. The fortress is dominated by five defensive towers, known as: English, Italian, German, French, and Serpent.

The construction of the English Tower, led by John Candall, was completed in 1480. The tower has two gates: one leads to the inner keep, and the other directly to the western ramparts. In the past, access to the tower was only possible via a drawbridge. On the western façade of the tower, a carved lion from the ancient period is visible, embedded in the building. For this reason, the tower is also called the Lion Tower. Above the figure of the lion, there is the coat of arms of King Henry IV of England. The same coat of arms was also placed above the lower entrance to the interior of the castle. On both sides of the royal coat of arms, there are the coats of arms of the monks and the coats of arms belonging to the noble families that financially supported the construction of the tower.

The French Tower is the highest structure in the Castle of St. Peter. It was designed by the Grand Master Philibert de Naillac himself, and his coat of arms is on the tower, along with those of the Pope and the King of France. The Italian Tower, built in 1436, was designed by the architect Angelo Mascettola.

The fortress under the Ottoman rule

In the 15th century, the Turks, led by Sultan Mehmed II, attempted to take St. Peter's Castle twice. The first attempt came just after they had taken Constantinople in 1453, and the second in 1480, only a year before the Sultan's death. In both cases, the attack was repelled by the Hospitallers. After these experiences, the monks decided to further strengthen the fortress by thickening its walls on the land side. At the beginning of the 16th century, Grand Master Fabrizio Del Carretto ordered an additional bastion to be built, also on the land side.

In 1520, Suleiman, later called the Magnificent, became the Ottoman sultan. Fearing an imminent Turkish attack, Grand Master Philippe Villiers de L'Isle-Adam ordered the castle to be re-fortified. The remaining materials from the Mausoleum were used for this purpose, so that almost nothing of the former Wonder of the World survived.

In June 1522, Sultan Suleiman attacked the headquarters of the Order of Saint John on the island of Rhodes. The fortress fell, after six months of fighting, in December 1522. The terms dictated by the victorious sultan required the Order of Saint John to hand over the fortress on the island of Kos and St. Peter's Castle in Petronium to the Turks.

After taking over St. Peter's Castle, the chapel on its premises was transformed into the Mosque of Suleiman (tr. Süleymaniye Camii). A minaret was added to the building, which was destroyed in 1915 during a bombardment by the French Navy. It was not rebuilt until 1997.

In 1846, the British ambassador to Constantinople, Lord Stratford Canning, obtained permission from the Sultan to dismantle twelve marble reliefs depicting the Amazonomachy, originally from the Mausoleum of Halicarnassus. Sir Charles Newton, who led the excavations in Bodrum, additionally removed several stone lions and one leopard from the castle. All of these exhibits are now on display at the British Museum in London.

For many centuries, St. Peter's Castle served as an Ottoman military base. In 1895, it was converted into a prison. After World War I, an Italian garrison was stationed in the fortress, but withdrew in 1921. From that moment on, the building stood empty for over 40 years and slowly fell into ruin.

Creation of the Museum of Underwater Archaeology

In 1962, the Turkish government decided to transform the fortress into a museum, the purpose of which was to exhibit ancient ships found in the Aegean Sea. The Museum of Underwater Archaeology has since become one of the most magnificent museums in Turkey, and the largest in the world dedicated to underwater archaeology.