After Pavia, the fate of the French king, and of France herself, becomes the subject of furious diplomatic maneuvering.

Charles V, lacking funds to pay for the war, decides to forgo the marriage into the House of Tudor which he had promised Henry VIII and seeks instead to marry Isabella of Portugal, who will bring with her a more substantial dowry.

Bourbon, meanwhile, plots with Henry to invade and partition France, and at the same time encourages d'Avalos to seize Naples and declare himself King of Italy.

Louise of Savoy's Regency and Diplomatic Efforts (1525)

Louise of Savoy, mother of King Francis I, acts as regent during her son's captivity following his defeat and capture at Pavia in February 1525. With France weakened and threatened by invasions, particularly an anticipated English incursion into Artois, Louise takes urgent action to protect French interests. She energetically mobilizes troops, raises funds, and attempts to stabilize France internally amidst rising fears of foreign invasion and internal dissent.

Seeking to open a new diplomatic front against the Habsburg emperor Charles V, Louise initiates France’s first direct diplomatic outreach to the Ottoman Sultan, Suleiman the Magnificent, requesting military assistance. This overture marks a significant and unprecedented effort at forming a Franco-Ottoman alliance, intended to counterbalance Habsburg dominance in Europe. However, this first mission tragically fails, as the French envoys are lost in Bosnia and never reach their destination.

Long-term Significance

Despite the initial failure, Louise's attempt at forging an alliance with the Ottoman Empire lays the groundwork for future diplomatic contacts between France and the Ottomans, significantly influencing European geopolitics for the remainder of the sixteenth century. Her regency showcases her political acuity and decisive action during a critical juncture, helping to maintain stability in France during her son's absence.

Francis, convinced that he will regain his freedom if he can obtain a personal audience with Charles, presses d'Avalos and Lannoy, who had intended to transport the king to the Castel Nuovo in Naples, to send him to Spain instead.

Concerned by Bourbon's scheming, they agree and Francis arrives in Barcelona on June 12.

Francis is initially held in a villa in Benisanó, near Valencia, but Charles, urged to negotiate a settlement by Montmorency and Lannoy, who suggests that the Italians will soon prove unfaithful to their Imperial alliance, orders the king brought to Madrid and imprisoned in the citadel here.

However, Charles adamantly refuses to receive Francis personally until the latter has accepted an agreement.

Meanwhile, Henry II of Navarre, who had fought alongside Francis at Pavia and who had been imprisoned in Madrid as well, escapes.

The struggle for Navarre continues, with Charles occupying the southern fringes of Lower Navarre and Henry remaining at large.

Charles demands not only the surrender of Lombardy, but also of Burgundy and Provence, forcing Francis to argue that French law prevents him from surrendering any lands possessed by the crown without the approval of Parlement, which will not be forthcoming.

Francis falls gravely ill in September, and his sister, Marguerite de Navarre, rides from Paris to join him in Spain.

The Imperial doctors examining the king believe that his illness is caused by his sorrow at not being received by the Emperor, and urge Charles to visit him.

Charles, against the advice of his Grand Chancellor, Mercurino Gattinara, who argues that seeing Francis on his deathbed is an action motivated by mercenary concerns rather than by compassion, and is thus unworthy of the Emperor, consents; and Francis soon makes a complete recovery.

An attempt to escape, however, proves fruitless, and succeeds only in getting Marguerite sent back to France.

Charles is by the beginning of 1526 faced with demands from Venice and the Pope to restore Francesco II Sforza to the throne of the Duchy of Milan, and has become anxious to achieve a settlement with the French before another war began.

Francis, having argued to retain Burgundy without result, is prepared to surrender it to achieve his own release.

On January 14, 1526, Charles and Francis agree to the Treaty of Madrid, by which the French king renounces all his claims in Italy, Flanders, and Artois, surrenders Burgundy to Charles, agrees to send two of his sons to be hostages at the Spanish court, and promises to marry Charles' sister Eleanor and to restore to Bourbon the territories that had been seized from him.

Francis, who holds the title of "Most Christian King", also agrees to persuade Henry to relinquish the throne of Navarre in favor of Charles "in order to uproot the errors of the Lutheran sect and the rest of condemned sects".

In December 1525, with France still reeling from King Francis I's capture at Pavia, a second French diplomatic mission—led by John Frangipani—successfully reaches the Ottoman capital of Constantinople. Louise of Savoy, acting as regent during Francis's captivity, had previously sought aid unsuccessfully; this second attempt carries urgent secret messages pleading for Ottoman assistance against the Habsburg Emperor Charles V, specifically requesting the sultan's aid in securing Francis’s release and mounting an offensive to relieve Habsburg pressure on France.

Frangipani returns to France on February 6, 1526, bearing Sultan Suleiman the Magnificent's favorable response. Suleiman's openness to the French overture signals the beginning of diplomatic relations between France and the Ottoman Empire. This unprecedented alliance across religious boundaries would soon reshape European geopolitics, dramatically altering traditional diplomatic dynamics.

Long-term Consequences and Significance

The Franco-Ottoman alliance, forged in desperation, evolves into a significant diplomatic and military relationship that will endure for decades. Suleiman’s entry into European affairs as a counterbalance to Habsburg dominance introduces a lasting complication into Christian Europe's political landscape, ultimately reshaping European diplomacy by establishing a powerful precedent for alliances across religious and cultural divides.

Francis I Released from Captivity (March 1526)

On March 6, 1526, King Francis I is finally released from captivity following the disastrous defeat at the Battle of Pavia(February 1525). Escorted northward by the Imperial envoy, Charles de Lannoy, Francis makes his way toward the French border. On March 18, he crosses the Bidasoa River into Fuenterrabia (Hondarribia), reentering French territory for the first time since his imprisonment.

The terms of his release under the Treaty of Madrid (January 1526) have imposed harsh conditions, including relinquishing claims to territories in Italy and Burgundy and the surrendering of his two young sons, the Dauphin Francisand Prince Henry, as hostages to guarantee compliance. Simultaneously with the king’s return, the princes, escorted by their grandmother and regent, Louise of Savoy, and the French commander Odet de Foix, Viscount of Lautrec, journey southward, crossing into Spain at Bayonne, beginning their captivity as hostages at the Spanish court.

The symbolic exchange underscores the deep personal and political cost of Francis’s capture and release, highlighting both his weakened diplomatic position and France’s determination to avoid the harshest consequences of defeat.

Long-term Consequences and Significance

Francis’s forced concessions to Charles V—including the handing over of his sons—will profoundly shape French foreign policy, fostering resentment and fueling Francis’s future attempts to overturn the humiliating conditions. His immediate rejection of the terms of the treaty upon his return sets the stage for renewed conflict, continued rivalry between France and the Habsburg Empire, and ultimately, the formation of alliances—including with the Ottoman Empire—designed to counterbalance Habsburg supremacy in Europe.

The Treaty of Hampton Court and the Diplomatic Shift (1526–1527)

By early 1526, King Francis I of France had successfully negotiated the Treaty of Hampton Court with England, drafted at Hampton Court Palace by Cardinal Thomas Wolsey and the French ambassador. The treaty signals a warming in Anglo-French relations, a diplomatic pivot facilitated by the evident failure of Henry VIII to gain substantial advantage from the earlier agreements associated with Francis's captivity. A French delegation officially ratifies this treaty at Greenwich in April 1527.

Despite this diplomatic breakthrough, Francis remains openly determined to defy the obligations he had reluctantly accepted under the Treaty of Madrid (January 1526). On March 22, 1526, Francis publicly repudiates the treaty, declaring it invalid because he had signed it under duress, a declaration supported implicitly by Pope Clement VII. Clement, deeply concerned about the rapidly expanding influence of Emperor Charles V in Italy, now sees the alignment of France and England as crucial in curbing Habsburg domination on the Italian peninsula. The Pope thus sends envoys urging Francis and Henry VIII to form a broader anti-Habsburg alliance.

Henry VIII, having benefited little from the Treaty of Madrid and increasingly wary of the Emperor's ambitions, proves receptive to Clement's overtures, setting the stage for a significant realignment of European alliances.

Long-term Consequences and Significance

Francis's repudiation of the Treaty of Madrid and the subsequent alignment with England and the Papacy represent a pivotal diplomatic shift, intensifying the enduring rivalry between the Valois and Habsburg dynasties. This realignment not only prolongs the Italian Wars but also precipitates events such as the War of the League of Cognac (1526–1530). Moreover, the growing closeness of England and France serves as an essential context for Henry VIII’s eventual break with Rome, underscoring how political alliances during this period become entangled with broader religious and ideological conflicts.

The League of Cognac: An Anti-Habsburg Alliance (May 1526)

In May 1526, the formation of the League of Cognac dramatically shifts the diplomatic landscape of Europe. Prompted by shared apprehension over Emperor Charles V's overwhelming dominance after the Battle of Pavia (1525), a coalition emerges comprising France, the Papacy, Venice, Florence, and Milan. This alliance, sponsored actively by Pope Clement VII, aims explicitly to curb Habsburg power, reclaim territories lost to Charles's expansion, and restore balance in Italian affairs.

The League, a direct reaction against Charles's hegemony in the Italian peninsula and his unprecedented control over European politics, illustrates how territorial, political, and religious interests intersected during this turbulent period. The alliance's formation marks a significant escalation in the ongoing Italian Wars, underscoring the volatile interplay between dynastic ambition and political equilibrium.

Long-term Consequences and Significance

The establishment of the League of Cognac initiates the War of the League of Cognac (1526–1530), drawing Europe deeper into conflict. Although intended to weaken Charles's grasp on Italy, the alliance ultimately leads to catastrophic consequences, most notably the infamous Sack of Rome in 1527 by imperial forces. This trauma severely weakens the Papacy and reshapes Europe's political and religious landscape, marking a turning point in the Italian Wars and setting the stage for decades of continued rivalry between France and the Habsburg Empire.