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The Pope as Peacemaker: Past and Present

Philippa Mesiano | National Lottery Heritage Fund

Shortly after the Russian invasion of Ukraine in February 2022, the papacy said it was prepared to assist in any negotiation aimed at ending this war. This offer was welcomed by the Ukrainian government and acknowledged by the Russians but has not progressed any further at this stage. It might seem surprising to observe an offer of papal mediation in the midst of a twenty-first-century conflict, especially one involving nations with relatively small Catholic communities, but there is a long precedent for papal mediation in international conflicts which dates back to the Middle Ages. From the eleventh century onwards, the pope firmly established his position as an international peacemaker with the power to facilitate, negotiate and settle disputes between secular rulers. While the pope frequently claimed this position as peacemaker to help end conflicts between kingdoms and nations, the motivations for and the overall effectiveness of papal intervention could vary wildly – somewhat shaped by each pope’s politics, theology, relations with those inside and outside the papal court, as well as the wider international context. I will explore one lesser-known example, that of Pope Alexander IV (1254 – 1261), who helped bring peace between England and France in 1259.

A sketch of Pope Alexander IV.
Figure 1: Sketch of Pope Alexander IV by seventeenth-century artist.


Alexander was keen for Henry III of England (1216 – 1272) to make peace with Louis IX of France (1226 – 1270) so that Henry could focus on supporting the pope’s ‘Crusade’ in Sicily – known as the Sicilian Business.

For many years the papacy was in conflict with the Hohenstaufen family, who had ruled over the Holy Roman Empire since the 12th century. The Kingdom of Sicily had been part of this Empire, but it was also a papal fiefdom – meaning it was under papal lordship, and as such, it was the pope’s right to appoint the ruler and vassal of this realm. Following the death of the Holy Roman Emperor and King of Sicily, Frederick II, on 13 December 1250, Pope Innocent IV (1243–1254) had become intent on ending imperial rule over the kingdom of Sicily and protecting his territory from this imposing threat on the doorstep of the Papal States, searching for a new claimant to the title. To make matters worse, in 1254 the illegitimate son of Frederick II, Manfred Lancia, effectively usurped the throne of Sicily from his infant nephew, Conradin.

For the first part of Henry’s reign, his relationship with the French king was fragile as he continued to press his hereditary claims to lands in France that had formerly belonged to his family, the Angevins. Louis saw this as a threat to the unity of his realm. A significant truce was agreed upon between Henry III and Louis IX in 1243, following Henry’s failed expedition to Poitou (1242–3). This truce was renewed in 1248, 1249 and 1250. With each renewal, the kings of England and France sought to extend peace so they could focus on their crusading efforts. In 1254 Louis IX returned from a failed crusade which had bankrupted his kingdom, and he aimed to build new alliances to protect his realm at this vulnerable time. He was ready to make a lasting peace with England. Henry needed more motivation, which had come in the form of the Sicilian Business.

A painting of the coronation of Henry III
Figure 2: The Coronation of Henry III

Innocent IV formally acquired help from Henry III in 1254 to resolve the succession problem in Sicily. It was agreed that Henry’s son Edmund would be crowned the new King of Sicily if, in return, Henry sent money and troops to Sicily to support the papal conflict against Manfred. For Henry, this was an attractive proposition. He was keen to extend his international territory, and Sicily was a wealthy and strategically placed kingdom which could benefit him greatly.

Innocent IV died on 7 December 1254. Having been informed that Henry might take longer than hoped to secure the funds for war, his successor, Pope Alexander IV, revised and renewed this agreement with Henry III in April 1255. He set a firm deadline – 1 October 1256 – by which time the English king had to send the money and troops. As part of this agreement, the pope had stipulated that Henry must form a lasting peace treaty with France. If Henry did not meet the terms of this agreement by the October deadline, he would face excommunication from the Church and his kingdom would be placed under interdict. Interdict and excommunication were the most severe ecclesiastical sanctions which could be imposed by the papacy. They effectively amounted to exclusion from the Christian community in Europe and all the associated benefits and protections.

A Map of Italy from 1902.
Figure 3: Historical Atlas of Modern Europe from the Decline of the Roman Empire comprising also Maps of Asia, Africa and the New World, ed. Reginald Poole (Oxford, 1902).


In 1257 formal peace negotiations began. Henry put together an embassy to send to France and petitioned the pope to send a papal representative to assist his envoys throughout these talks. The pope sent a Franciscan friar, Brother Mansuetus, to help negotiate on the English king’s behalf. Alexander IV often utilised Franciscans as papal representatives, and he had a close bond with the order throughout his career. He was the Cardinal Protector of the Franciscan order from 1227 until his death in 1261. It was his duty to support and present their interests to the papal court both before and after he was elected to the papal throne.

This embassy failed to agree on peace terms as the French would not concede to Henry’s demands to reclaim former Angevin territory in France.

After several delays and extensions to the original deadline stipulated in the Sicilian Agreement, the papal envoy, Master Arlot, had threatened the English king and his baronial council with excommunication and interdict in May 1258 if they did not quickly fulfil their obligations to the papacy, which included securing peace with France. Henry sent another delegation to Paris accompanied by Mansuetus, who was to report back to the pope on the final terms of the treaty.

The articles of the treaty of Paris were agreed on 28 May 1258 and published on 4 December 1259, by which point the pope had actually abandoned the Sicilian Business – cancelled in December 1258 due to Henry’s inability to fully commit.

The success of this treaty was not dependent on papal assistance but was helped along by the intervention. It was built on the willingness of the English and French kings to secure peace. In Louis’ case, it was to protect his realm from potential invasion. In Henry’s case, it was the Sicilian throne which motivated him. For Alexander IV, it was the opportunity to rid Sicily of a papal foe while also upholding his image as a peacemaker and spiritual leader.

Franciscan Ideals

There are some striking similarities between Pope Alexander IV and Pope Francis in their method and style of leadership and depiction of their international position.

Both Alexander IV and Francis were inspired by the teachings of St Francis of Assisi (1226), the founder of the Franciscan Order. St Francis was a man of peace who taught his followers to live a humble and simple life. Alexander was a supporter of the Franciscans, utilising their theology, popularity, mobility and education for his political and spiritual aims. Inspired by the friars to use the language of peace to justify his intervention in political matters, it also helped propagate his image as a peacemaker. Pope Francis took his papal name from the same St Francis. He has been dedicated to the promotion of peace throughout his pontificate. He assisted the US and Cuba in stabilising their relationship in 2014 and helped Columbia’s government reach a truce with FARC, a rebel organisation, in 2016. In his 2022 New Year’s Day Address, he condemned violence against women and urged the world to roll up its sleeves for peace. If nothing else, he strives to be remembered as a promoter and facilitator of peace on Earth.

Popes can assist in the facilitation of peace, but there is some limit to what they can achieve if the warring parties are not both on board with the idea. Like Alexander IV, Francis has been influenced by Franciscan teachings, using the language of peace to promote and justify their papal right to intervene on an international stage. However, as the role of the papacy has changed over the years, so have the methods used by popes. While both their motivations and actions derive from a Franciscan desire for peace, Alexander IV came from a position of active political entanglement, whereas Francis does not. Regardless, peacekeeping has remained an important feature of the papacy, and despite the many years that separate these two popes, they both strove to make it a central component of their rule. Francis is highlighting his spiritual authority in his offer to mediate an end to this current conflict, utilising this constant component of the papal office to help secure a swift peace in Ukraine.


Further Reading:

  • Carpenter, David, ‘King Henry III and the Sicilian Affair’, Fine of the Month (Feb., 2012), Henry III Fine Rolls Project, Available online at:

  • Chaplais, Pierre, ‘The Making of the Treaty of Paris (1259) and the Royal Style’, English Historical Review, 67. 263 (1952), 235 ̶ 253

  • Mesiano, Philippa J., ‘The use of Friars as Royal and Papal Envoys: Diplomatic relations between Henry III and Pope Alexander IV (1254–1261)’ in Thirteenth Century England XVII, ed. Andrew M. Spencer and Carl Watkins (Woodbridge, 2021)

  • Weiler, Björn K. U., ‘Henry III and the Sicilian Business: A Reinterpretation’, Historical Research, 74 (2001), 127–50

  • Whalen, Brett Edward, The Medieval Papacy (Basingstoke, 2014)

Dr Philippa Mesiano completed her PhD at the University of Kent in 2020. Her research explored the diplomatic relationship between King Henry III of England (1216 - 1272) and Pope Alexander IV (1254 - 1261), focusing on the methods, agents and language utilised throughout these exchanges. She now works in heritage engagement and interpretation.

Twitter: @PhilippaMesiano


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