Gardiki sits on the border where Messenia meets Arcadia, in the uplands roughly 25 kilometers north of Kalamata. Its position made it strategically significant in a century of almost continuous warfare between the Byzantine Despotate of the Morea and the Latin Principality of Achaea. By 1297, the castle was firmly in Byzantine hands — its presence so threatening to the Frankish-controlled lowlands that the Princess of Achaea, Isabella of Villehardouin, constructed an entirely new fortress called Chateneuf specifically to protect the inhabitants of the Messenian and Arcadian plains from Byzantine raiding parties based at Gardiki and the nearby stronghold of Mystras. The record of Gardiki's tenure suggests it was almost certainly built by the Byzantines: no account records it ever having been held by the Latin lords of Achaea.

In 1374, Francis of San Severino arrived as the new bailli — viceroy — of the Principality of Achaea and immediately moved against Gardiki. His forces captured the village at the castle's foot and defeated a Byzantine relief force sent to dislodge him. But the castle itself did not fall. The fortifications had been built for precisely this kind of pressure, and San Severino, unable to break through, was forced to withdraw. The victory was incomplete. The Byzantines held their ground on the hill. The Franks retained the plains. The standoff that had defined this border for nearly a century continued. Gardiki's walls, wherever they precisely stood, had done their job.

By the early fifteenth century, a new threat had rendered the Byzantine-Frankish conflict secondary. The Ottoman Empire was pressing against the Morea from the north. In 1422, the Republic of Venice considered absorbing Gardiki and neighboring fortresses — along with much of what remained of both the Principality of Achaea and the Byzantine Despotate — into a defensive alliance. Negotiations with the local Latin and Greek lords came to nothing. The following year, Ottoman forces under Turahan Bey invaded the Morea, and Gardiki was among the towns captured and pillaged. The fortress survived, as fortresses sometimes do. The political framework around it did not.

The story of Gardiki Castle ends in 1460, during the final Ottoman conquest of the Morea. The population of the nearby town of Leontari fled to the castle seeking safety, as people in the region had sought safety at Gardiki for nearly two centuries. Manuel Bochalis commanded the garrison. He negotiated a surrender on condition that the lives of everyone inside would be spared. The Ottomans agreed. They then massacred the entire population of 6,000 people sheltering within the walls. Only Bochalis and his immediate family were spared — because they happened to be relatives of the Ottoman grand vizier, Mahmud Pasha Angelovic. Their connection saved their lives; no one else's connection was enough. The location of the castle itself is now uncertain. Medieval sources describe a site that does not match the village of Gardiki near modern Anavryto to the east of Leontari, where no traces of fortification survive. Scholars believe the actual castle may lie southwest of Leontari, at ruins near a place called Kokla or Kokkala, close to Ellinitsa — a site proposed by earlier historians Pietro Antonio Pacifico and Jean Alexandre Buchon. The ground that witnessed those events has not yet confirmed it.