Wars of Castro The Wars of Castro were a series of conflicts during the mid - 17th century revolving around the ancient city of Castro ( located in present - day Lazio , Italy ) , which eventually resulted in the city ' s destruction on 2 September 1649 . The conflict was a result of a power struggle between the papacy – represented by members of two deeply entrenched Roman families and their popes , the Barberini and Pope Urban VIII and the Pamphili and Pope Innocent X – and the Farnese dukes of Parma , who controlled Castro and its surrounding territories as the Duchy of Castro . Precursors . Papal politics of the mid - 17th century were complicated , with frequently shifting military and political alliances across the Catholic world . While it is difficult to trace the precise origins of the feud between the duchy of Parma and the papacy , its origins can be looked for in political maneuverings occurring in the years or even decades preceding the start of military action . In 1611 a group of conspirators , nobles from Modena and Mantua , was accused of devising a plot to assassinate Ranuccio I Farnese , Duke of Parma and other members of the Farnese family in Parma . In reality , the plot had been " " uncovered " " when a prisoner ( being held for unrelated crimes ) confessed to it and implicated members of various noble houses . Though the accusations were likely untrue , 100 of the " " conspirators " " were tortured and eventually executed in Parma ' s main square in 1612 . Many of their estates were confiscated leaving a large number of now legitimately discontented nobles . Until his death in 1622 , Ranuccio remained paranoid about future assassination attempts and about curses from witches and heretics . He persecuted " witches " and alleged conspirators savagely and even had his own mistress , Claudia Colla , burned to death . He remained convinced that other noble families were plotting his downfall . However , tensions between the Farnese and other Italian nobility were not limited to local events in Parma . Historian Leopold von Ranke gives an account of a 1639 visit to Rome by Odoardo Farnese , Duke of Parma and Piacenza . The Duke arrived in Rome to great fanfare - he was given gifts and escorted around the city by Pope Urban ' s Cardinal - nephew s , Antonio Barberini and Francesco Barberini . But the Duke refused to pay due deference to the Pope ' s other nephew ; the newly appointed Prefect of Rome , Taddeo Barberini . As the Duke prepared to leave , he suggested that an escort from the city ( ordinarily reserved for the Grand Duke of Tuscany ) would be appropriate . Francesco Barberini refused . The Duke took his leave but urged the Pope to chastise both Cardinal - nephews . The nephews were furious and convinced the pope to punish the Duke by banning grain shipments originating in Castro from being distributed in Rome and the surrounding territory , thereby depriving the Duke of an important source of income . Duke Odoardo ' s Roman creditors saw their chance - the Duke was unable to pay his debts , which he had accumulated in military adventures against the Spanish in Milan and in luxurious living . The unpaid and unhappy creditors sought relief from the pope , who turned to military action in an attempt to force payment . Preparations for war . Pope Urban VIII responded to the requests of Duke Odoardo ' s creditors by sending his nephew Antonio , Fabrizio Savelli and Marquis Luigi Mattei to occupy the city of Castro . Papal forces also included commanders Achille d ' Étampes de Valençay and Marquis Cornelio Malvasia . At the same time , the pope sent cardinal Bernardino Spada as plenipotentiary in an effort to resolve the crisis . Spada successfully negotiated a truce but when the pope ' s military leaders became aware that the dukes were massing troops to counter their own ( in case discussions with Spada came to naught ) , Urban VIII declared the articles of peace null and void and claimed Spada had negotiated them without his consent . Spada later published a manifesto detailing his version of events which , according to contemporary John Bargrave , many accepted to be the truth . Indeed , Urban VIII had been amassing troops in Rome throughout 1641 . Mercenaries and regular troops filled the streets and Antonio Barberini was forced to institute special measures to maintain authority over the city . But the papacy needed yet more troops . The Duke of Ceri , who had been imprisoned for wounding a papal officer in a dispute over the management of the Duchy of Ceri , and Mario Frangipani , imprisoned for murdering someone on his estate , were both pardoned by the pope and given command of papal troops . First War of Castro . On 12 October 1641 , Luigi Mattei led 12 , 000 infantry and up to 4 , 000 cavalry against the fortified town . The pope ' s forces were met by a contingent of 40 troops guarding a bridge leading to the town ; a short burst of cannon - fire resulting in a single death was enough to prompt capitulation . Castro , and several other small towns nearby , surrendered . Fabrizio Savelli , though , proved to be an unenthusiastic commander . The army was split into three and the Pope ' s nephew , Taddeo Barberini , replaced Savelli as Generalissimo , arriving with one contingent in the papal city of Ferrara on 5 January 1642 . On 11 January the opera " L ' Armida " , by Barberini house composer Marco Marazzoli , was presented in his honour and Marazzoli composed a work " Le pretensioni del Tebro e del Po " to commemorate recent events . On 13 January , Urban excommunicated Odoardo and rescinded his fiefdoms ( which had been granted by Pope Paul III – Odoardo ' s great - great - great - grandfather – in 1545 ) . Odoardo countered with a military march of his own , this time on the papal state itself and his forces were soon close enough to threaten Rome . But Odoardo faltered and the Pope was able to fortify Rome and raise a new army - this time 30 , 000 troops ; enough to drive the Duke back to his own territory . Odoardo forged alliances with the Venice , Modena , and Tuscany which was under the command of his brother - in - law , Ferdinando II de ' Medici , Grand Duke of Tuscany . At first , Pope Urban threatened to excommunicate anyone who helped Odoardo , but Odoardo ' s allies insisted their conflict was not with the papacy , but rather with the Barberini family ( of which the Pope happened to be a member ) . When this failed , the Pope attempted to call on old alliances of his own and turned to Spain for assistance . But he received little help as Spanish forces were fully occupied by the Thirty Years ' War . As it was , most of the troops fighting on the side of the papacy were French , most of those fighting for the Dukes were German . Exasperated , the Pope increased taxes and raised additional forces and the war continued with Cardinal Antonio Barberini ( Taddeo ' s brother ) finding success against the Venetians and Modenese . But Papal forces suffered significant defeats in the area around Lake Trasimeno at the hands of the Tuscans ( the " Battle of Mongiovino " ) . Fighting in the style typical of 17th century Europe , by the latter half of 1643 neither side had made significant ground , though both sides had spent significant amounts of money perpetuating the conflict . It has been suggested that Pope Urban and forces loyal to the Barberini spent some 6 million thaler s during the 4 years of the conflict that fell within Pope Urban ' s reign . The papal forces suffered a crucial defeat at the " Battle of Lagoscuro " on 17 March 1644 and were forced to surrender . Antonio Barberini was almost captured ; saved , " " only by the fleetness of his horse " " . Peace was agreed to in Ferrara on 31 March . Under the terms of the peace , Odoardo was readmitted to the Catholic Church and his fiefdoms were restored to him . Grain shipments from Castro to Rome were once again allowed and Odoardo was to resume payments to his Roman creditors . This peace settlement concluded the First War of Castro and was widely considered a disgrace to the papacy , which was unable to impose its will through use of military force . Urban is said to have been so distressed that after signing the peace agreements he was overcome by a severe malady which stayed with him until his death . Urban ' s death and Barberini exile . Pope Urban VIII died just a few months after the peace settlement was agreed to , on 29 July 1644 and on 15 September Pamphili family Pope Innocent X was elected to replace him . Almost immediately , Innocent X began an investigation into the financing of the conflict . In total , the first war is estimated to have cost the papacy 12 million scudi and special taxes were levied against the residents of Rome to refill church coffers . The nephews of Pope Urban VIII who had led the papal armies , brothers Antonio Barberini ( Antonio the Younger ) , Taddeo Barberini and Francesco Barberini , were forced to abandon Rome and flee to France , assisted by Cardinal Mazarin . There they depended on the hospitality of Louis XIV , King of France . Taddeo Barberini died in Paris in 1647 but in 1653 Antonio and Francesco Barberini were allowed to return to Rome after sealing a reconciliation with Innocent X through the marriage of Taddeo ' s son Maffeo Barberini and Olimpia Giustiniani ( a niece of Innocent X ) . Relations were also later repaired with some of Odoardo ' s former allies when Taddeo ' s daughter , Lucrezia Barberini married Francesco I d ' Este , Duke of Modena who had led Modenese forces against the Barberini . Second War of Castro . With peace agreed to and with Barberini power - brokers dead or exiled , the citizens of Castro were left alone . But Odoardo Farnese , who had signed the original peace accord , died in 1646 and was succeeded by his son Ranuccio II Farnese , Duke of Parma . In 1649 , Ranuccio refused to pay Roman creditors as his father had agreed in the treaty signed five years prior . He also refused to recognize the new bishop of Castro , Monsignor Cristoforo Giarda , appointed by Pope Innocent X . When the bishop was killed en route to Castro , near Monterosi , Pope Innocent X accused Duke Ranuccio , and his supporters , of murdering him . In retaliation for this alleged crime , forces loyal to the Pope marched on Castro . Ranuccio attempted to ride out against the Pope ' s forces but was routed by Luigi Mattei . On 2 September , on the Pope ' s orders , the city was completely destroyed . Not only did Pope Innocent ' s troops destroy the fortifications and general buildings of Castro , they destroyed the churches as well so as to completely sever all links between the city and the papacy . As a final insult , the troops destroyed Duke Ranuccio ' s family " Palazzo Farnese " and erected a column reading " Quì fu Castro " ( " Here stood Castro " ) . Duke Ranuccio II was forced to cede control of the territories around Castro to the pope , who then attempted to use the land to settle debts with the Ranuccio ' s creditors . This marked the end of the Second War of Castro and the end of Castro itself – the city was never rebuilt .