[8] Mediterranean In 1533, Suleiman the Magnificent ordered Hayreddin Barbarossa, whom he had summoned from Algiers, to build a large war fleet for Constantinople.

[15] Unexpectedly, the funding of the conquest of Tunis came from the galleons sailing in from the New World, in the form of two million gold ducats extracted by Francisco Pizarro for releasing the Inca king Atahualpa, whom he nevertheless executed on 29 August 1533.

[15] Despite a request by Charles V, Francis I denied French support to the expedition, explaining that he was under a three-year truce with Barbarossa following the 1533 Ottoman embassy to France.

In the action, the Portuguese galleon São João Baptista distinguished itself by breaking the chains protecting the harbour's entrance, thereafter opening fire on La Goletta.

The siege demonstrated the power of the Habsburg dynasties at the time; Charles V had under his control much of southern Italy, Sicily, Spain, the Americas, Austria, the Netherlands, and lands in Germany.

[19][20][21] The Spanish governor of La Goulette, Luys Peres Varga, fortified the island of Chikly in the lake of Tunis to strengthen the city's defences between 1546 and 1550.