Historians have emphasized the importance of gunpowder technology, new styles of fortification to resist cannon fire, and the increased professionalization of the soldiers.

An early offensive into Lorraine, in the Second Schmalkaldic War, was successful, with Henry capturing the Three Bishoprics of Metz, Toul, and Verdun and securing them by defeating the invading Habsburg army at the Battle of Renty (12 August 1554).

In 1552, an anti-Spanish revolt in the Republic of Siena gave Henry another ally; on 17 July 1552, a Franco-Sienese army managed to expel the Spanish garrison.

[11] After Emperor Charles' abdication in 1556 split the Habsburg empire between Philip II of Spain and Ferdinand I, the focus of the war shifted to Flanders.

Pope Paul IV was displeased and urged Henry II to join the Papal States in an invasion of Spanish Naples.

Out of fear of another sack of Rome, Paul IV agreed to the Duke of Alba's demand for the Papal States to declare neutrality by signing the Peace of Cave-Palestrina (12 September 1557).

[13] A brief French-backed revolt led by Thomas Stafford against queen Mary I of England resulted in a three-day siege of Scarborough Castle in April 1557.

French armies plundered Spanish possessions in the Low Countries[clarification needed] and emerged victorious in the Siege of Thionville (April–June 1558).

Nonetheless, Henry lost gravely at the Battle of Gravelines (13 July 1558) and was forced to accept a peace agreement in which he renounced any further claims to Italy.

Credit at this point began costing the crown 43 percent interest (largely financed by the Fugger and Welser banking families).

[18] The two treaties also defined the conclusion of the Imperial-French wars and therefore the end of the Habsburg-Valois conflict as a whole, with the approval of Ferdinand I, Holy Roman Emperor.

[22] Some Italian states also attended the conference - for instance, Ottavio Farnese, Duke of Parma sent the Mantuan Curzio Gonzaga as his delegate.

[32] During a tournament held to celebrate the peace on 1 July, king Henry was injured in a jousting accident when a sliver from the shattered lance of Gabriel Montgomery, captain of the Scottish Guard at the French Court, pierced his eye and entered his brain.

[33] The resulting political instability, combined with the sudden demobilisation of thousands of largely unpaid troops, led to the outbreak of the French Wars of Religion in 1562 that would consume France for the next thirty years.

[35] The most significant Italian power left was the papacy in central Italy, as it maintained major cultural and political influence during the Catholic Reformation.