When the Ottomans completed Bouka in 1478, a small settlement formed to the north of its walls. The castle was known in Turkish as Preveze kalesi — the castle in the Passage — and the settlement took the same name, Preveza. The first dated document to record that name comes from 1481, a letter from a Venetian official in Corfu. Leonardo III Tocco, Count of Cephalonia, had already written to Venice three years earlier warning that this new castle at the mouth of the gulf was a threat to Venetian maritime interests. His letter referred to it as 'castello ala bucca delo gulfo' — the castle at the mouth of the gulf. He was right to worry. The castle that gave Preveza its name would prove one of the most strategically contested positions in the eastern Mediterranean for the next two centuries.

In 1481 — just three years after construction — a small Catalan fleet of twelve galleys and nine smaller vessels under a captain named Vilamarino arrived at the gulf entrance, found only fifteen Turkish soldiers defending the new castle, and temporarily seized it. They looted it and moved on. That raid set the pattern. The Ottomans reinforced Bouka in 1486–87, again in 1495, 1502, 1530, and 1552 under Suleiman the Magnificent. In 1538, the Ottoman fleet under Hayreddin Barbarossa used the castle as a base during the sea battle of Preveza, defeating the combined Christian fleets of Europe. In 1501, Venetian forces under Vice-Admiral Benedetto Pesaro engaged the castle while raiding the gulf. In 1605, the Knights of Saint Stephen from Pisa landed near Preveza by night, bombarded the castle at dawn, forced the Ottoman garrison of 80–100 men to surrender, and spent a day plundering the town — taking roughly 250 inhabitants, both Muslim and Christian, as captives before releasing the Christians at Antipaxoi and departing.

Around 1670, the Ottoman traveler Evliya Çelebi visited Preveza and left a precise description of what he found. The castle was garrisoned by 250 soldiers. Inside the walls: narrow streets, about 100 small houses without gardens, a mosque built by Sultan Suleiman I. Outside the walls: 300 larger houses with gardens and a bazaar of 100 shops. It was a functioning small town wrapped around a military installation at one of the most strategically important passages in Greece. Fourteen years after Çelebi's visit, the Venetians would take it.

On 29 September 1684, at the start of the Morean War, the Venetians captured the Castle of Bouka and immediately set about improving it — widening the moat, strengthening the walls, adapting the fortification to their own defensive needs. They held it for seventeen years. When the Treaty of Karlowitz in 1699 obliged the Venetians to return Preveza to Ottoman control, they faced a choice. Handing back a strengthened, well-maintained fortress felt strategically unacceptable. In 1701, before the handover, they demolished it. The site the Venetians left behind was called Paliosaraga — Old Seraglio. In the early 1810s, Ali Pasha of Yannina built his summer residence on the ruins. After the Greek Army captured Preveza in 1912, a military supply unit occupied the site. Today very little of the castle remains, and the ground has not been substantially built upon — an absence that somehow suits a place that was built to hold a passage and ended by being erased.