Bodrum Castle - Castle of St. Peter  

Confronted with the invasion of Seljuk Turks, the Knights Hospitaller, with their headquarters on the island of Rhodes, needed another stronghold on the mainland. Grand Master Philibert de Naillac (1396-1421) found a suitable site across the island of Kos, where there was already a castle of the Order. This location had been already the site of a fortification in Doric times (1110 BC) and of a small Seljuk castle in the 11th century. The same promontory was also the probable site of the palace of Mausolos, the famous king of Caria.

The construction of the castle started in 1402 under the German knight-architect Heinrich Schlegelholt. Construction workers were guaranteed a reservation in Heaven by a papal decree of 1409. They used squared green volcanic stone, marble colums and reliefs from the nearby Mausoleum of Maussollos to fortify the castle. The first walls were completed in 1437. The chapel was among the first completed inner structures (probably 1406). It consists of a vaulted nave and an apse. The chapel was reconstructed in Gothic style by Spanish Knights in 1519-1520. Their names can be found on two cornerstones of the facade.

Fourteen cisterns for collecting rainwater were excavated in the rocks under the castle.

Each tongue of the Order had its own tower, each in his own style and the French tower being the tallest. Each tongue, each headed by a bailli, was responsible for the maintenance and defence of a specific portion of the fortress and responsible for manning it with sufficient numbers of knights and soldiers. There were seven gates leading to the inner part of the fortress. The architect had applied the latest in castle design : the passages leading to these gates were full of twists and turns. Eventual assailants could not find cover against the arrows, stones or heated projectiles they had to confront. The Knights had placed above the gates and on the walls hundreds of painted coats of arms and carved reliefs. There remain now 249 separate designs : those of grand masters, castle commandants, countries, personal coat of arms of knights and religious figures.

The construction of the three-storied English tower was finished in 1413. One door opens to the north, to the inner part of the castle; The other door leads to the western rampart. One could only access this tower via a drawbridge. The western façade shows an antique carved relief of a lion. Because of this relief, the tower was also called "the Lion Tower". Above this lion, one can see the coat of arms of king Henry IV of England.

For over a century St. Peter's Castle remained the second most important castle of the Order. It served as a refuge for all Christians in Asia Minor.

The castle came under attack with the rise of the Ottoman Empire, first after the fall of Constantinople in 1453 and again in 1480 by sultan Mehmed II. The attacks were repelled by the Knights.

In 1482, Prince Cem, son of sultan Mehmed II and brother of sultan Bayezid II, sought refuge in the castle, after a failure in raising a revolt against his brother.

When the Knights decided to fortify the castle in 1494, they used again stones of the Mausoleum. The walls facing the mainland were thickened as to withstand the increasing destructive power of canons. The walls facing the sea were less thick, since the Order had little to fear from a sea attack, since they had a powerful fleet. Grand Master Fabrizio Del Carretto (1513-21) built a round bastion to strengthen the land side of the fortress.

Sir Thomas Docwra was captain of the castle in 1499.