Battle of Bicocca The Battle of Bicocca or La Bicocca ( ) was fought on 27 April 1522 , during the Italian War of 1521 – 26 . A combined French and Venetian force under Odet de Foix , Vicomte de Lautrec , was decisively defeated by a Spanish - Imperial and Papal army under the overall command of Prospero Colonna . Lautrec then withdrew from Lombardy , leaving the Duchy of Milan in Imperial hands . Having been driven from Milan by an Imperial advance in late 1521 , Lautrec had regrouped , attempting to strike at Colonna ' s lines of communication . When the Swiss mercenaries in French service did not receive their pay , however , they demanded an immediate battle , and Lautrec was forced to attack Colonna ' s fortified position in the park of the Arcimboldi Villa Bicocca , north of Milan . The Swiss pikemen advanced over open fields under heavy artillery fire to assault the Imperial positions , but were halted at a sunken road backed by earthworks . Having suffered massive casualties from the fire of Spanish arquebus iers , the Swiss retreated . Meanwhile , an attempt by French cavalry to flank Colonna ' s position proved equally ineffective . The Swiss , unwilling to fight further , marched off to their canton s a few days later , and Lautrec retreated into Venetian territory with the remnants of his army . The battle is noted chiefly for marking the end of the Swiss dominance among the infantry of the Italian Wars , and of the Swiss method of assaults by massed columns of pikemen without support from other troops . It was also one of the first engagements which established the decisive role of firearms on the battlefield . Prelude . At the start of the war in 1521 , Holy Roman Emperor Charles V and Pope Leo X moved jointly against the Duchy of Milan , the principal French possession in Lombardy . A large Papal force under Federico II Gonzaga , Duke of Mantua , together with Spanish troops from Naples and some smaller Italian contingents , concentrated near Mantua . The German forces which Charles sent south to aid this venture passed through Venetian territory near Vallegio unmolested ; the combined Papal , Spanish , and Imperial army then proceeded into French territory under the command of Prospero Colonna . For the next several months , Colonna fought an evasive war of maneuver against Odet de Foix , Vicomte de Lautrec , the French commander , besieging cities but refusing to give battle . By the autumn of 1521 , Lautrec , who was holding a line along the Adda river to Cremona , began to suffer massive losses from desertion , particularly among his Swiss mercenaries . Colonna took the opportunity this offered and , advancing close to the Alps , crossed the Adda at Vaprio ; Lautrec , lacking infantry and assuming the year ' s campaign to be over , withdrew to Milan . Colonna had no intention of stopping his advance , however . On the night of November 23 , he launched a surprise attack on the city , overwhelming the Venetian troops defending one of the walls . Following some abortive street - fighting , Lautrec withdrew to Cremona with about 12 , 000 men . By January , the French had lost Alessandria , Pavia , and Como ; and Francesco II Sforza , bringing further German reinforcements , had slipped past a Venetian force at Bergamo to join Colonna in Milan . Lautrec had meanwhile been reinforced by the arrival of 16 , 000 fresh Swiss pike men and some further Venetian forces , as well as additional companies of French troops under the command of Thomas de Foix - Lescun and Pedro Navarro ; he had also secured the services of the condottiere Giovanni de ' Medici , who brought his Black Bands into the French service . The French proceeded to attack Novara and Pavia , hoping to draw Colonna into a decisive battle . Colonna , leaving Milan , fortified himself in the monastery of Certosa south of the city . Considering this position to be too strong to be easily assaulted , Lautrec attempted instead to threaten Colonna ' s lines of communication by sweeping around Milan to Monza , cutting the roads from the city into the Alps . Lautrec was suddenly confronted , however , with the intransigence of the Swiss , who formed the largest contingent of the French army . They complained that they had not received any of the pay promised them since their arrival in Lombardy . The Swiss captains , led by Albert von Stein , demanded that Lautrec attack the Imperial army immediately — else the mercenaries would abandon the French and return to their canton s . Lautrec reluctantly acquiesced and marched south towards Milan . Battle . Dispositions . Colonna had meanwhile relocated to a formidable new position : the manor park of Bicocca , about four miles ( 6 km ) north of Milan . The park was situated between a large expanse of marshy ground to the west and the main road into Milan to the east ; along this road ran a deep wet ditch , which was crossed by a narrow stone bridge some distance south of the park . The north side of the park was bordered by a sunken road ; Colonna deepened this and constructed an earthen rampart on the southern bank . The Imperial artillery , placed on several platforms jutting forward from the earthworks , was able to sweep the fields north of the park as well as parts of the sunken road itself . The entire length of the north side of the park was less than , which permitted Colonna to place his troops quite densely . Immediately behind the rampart were four ranks of Spanish arquebus iers , commanded by Fernando d ' Avalos , Marquess of Pescara ; they were backed by Spanish pike men and German landsknechts under Georg Frundsberg . Most of the Imperial cavalry was placed at the south end of the park , far behind the infantry ; a separate force of cavalry was positioned to the south , guarding the bridge . On the evening of 26 April , Lautrec sent a force of about 400 cavalry under the Sieur de Pontdormy to reconnoiter the Imperial positions . The patrol reported that the ground was cut by irrigation ditches and ill - suited for maneuvering , but this failed to dissuade the Swiss . Colonna , having observed the French presence , sent messengers to Milan to request reinforcements ; Francesco Sforza arrived the next morning with 6 , 400 additional troops , joining the cavalry near the bridge to the south of Colonna ' s camp . At dawn on 27 April , Lautrec began his attack . The Black Bands brushed aside the Spanish pickets , clearing the ground before the Imperial positions . The French advance was headed by two columns of Swiss , each comprising about 4 , 000 to 7 , 000 men , accompanied by some artillery ; this party was to assault the entrenched front of the Imperial camp directly . Lescun , meanwhile , led a body of cavalry south along the Milan road , intending to flank the camp and strike at the bridge to the rear . The remainder of the French army , including the French infantry , the bulk of the heavy cavalry , and the remnants of the Swiss , formed up in a broad line some distance behind the two Swiss columns ; behind this was a third line , composed of the Venetian forces under Francesco Maria della Rovere , the Duke of Urbino . The Swiss attack . The overall command of the Swiss assault was given to Anne de Montmorency . As the Swiss columns advanced towards the park , he ordered them to pause and wait for the French artillery to bombard the Imperial defences , but the Swiss refused to obey . Perhaps the Swiss captains doubted that the artillery would have any effect on the earthworks ; historian Charles Oman suggests that it is more likely they were " inspired by blind pugnacity and self - confidence " . In any case , the Swiss moved rapidly towards Colonna ' s position , leaving the artillery behind . There was apparently some rivalry between the two columns , as one , commanded by Arnold Winkelried of Unterwalden , was composed of men from the rural cantons , while the other , under Albert von Stein , consisted of the contingents from Bern and the urban cantons . The advancing Swiss quickly came into range of the Imperial artillery . Unable to take cover on the level fields , they began to take substantial casualties ; as many as a thousand Swiss may have been killed by the time the columns reached the Imperial lines . The Swiss came to a sudden halt as the columns reached the sunken road in front of the park ; the depth of the road and the height of the rampart behind it — together higher than the length of the Swiss pikes — effectively blocked their advance . Moving down into the road , the Swiss suffered massive casualties from the fire of d ' Avalos ' s arquebusiers . Nevertheless , the Swiss made a series of desperate attempts to breach the Imperial line . Some parties managed to reach the top of the rampart , only to be met by the landsknechts , who had come up from behind the arquebusiers . One of the Swiss captains was apparently killed by Frundsberg in single combat ; and the Swiss , unable to form up atop the earthworks , were pushed back down into the sunken road . After attempting to move forward for about half an hour , the remnants of the Swiss columns retreated back towards the main French line . In the fields which they had crossed and before the rampart , they left more than 3 , 000 dead ; among these were twenty - two captains , including both Winkelried and Albert von Stein . Of the French nobles who had accompanied the Swiss assault , only Montmorency survived . Denouement . Lescun , with about 400 heavy cavalry under his command , had meanwhile reached the bridge south of the park and fought his way across it and into the Imperial camp beyond . Colonna responded by detaching some cavalry under Antonio de Leyva to halt the French advance , while Francesco Sforza came up the road towards the bridge , aiming to surround Lescun . Pontdormy held off the Milanese , allowing Lescun to extricate himself from the camp ; the French cavalry then retraced its path and rejoined the main body of the army . Despite the urging of d ' Avalos and several other Imperial commanders , Colonna refused to order a general attack on the French , pointing out that much of Lautrec ' s army — including the bulk of his cavalry — was still intact . Colonna suggested that the French were already beaten , and would soon withdraw ; this assessment was shared by Frundsberg . Nevertheless , some small groups of Spanish arquebusiers and light cavalry attempted to pursue the withdrawing Swiss , only to be beaten back by the Black Bands , which were covering the removal of the French artillery from the field . Colonna ' s judgement proved to be accurate . The Swiss were unwilling to make another assault , and marched for home on 30 April . Lautrec , believing that his resulting weakness in infantry made a further campaign impossible , retreated to the east , crossing the Adda into Venetian territory at Trezzo . Having reached Cremona , Lautrec left Lescun in command of the remnants of the French army and rode unescorted to Lyon , to make his report to Francis I . Aftermath . Lautrec ' s departure heralded a complete collapse of the French position in northern Italy . No longer menaced by the French army , Colonna and d ' Avalos marched on Genoa , capturing it after a brief siege . Lescun , learning of the loss of Genoa , arranged an agreement with Francesco Sforza by which the Castello Sforzesco in Milan , which still remained in French hands , surrendered , and the remainder of the French forces withdrew over the Alps . The Venetians , under the newly elected Doge Andrea Gritti , were no longer interested in continuing the war ; in July 1523 , Gritti concluded the Treaty of Worms with Charles V , removing the Republic from the fighting . The French would make two further attempts to regain Lombardy before the end of the war , but neither would be successful ; the terms of the Treaty of Madrid , which Francis was forced to sign after his defeat at the Battle of Pavia , would leave Italy in Imperial hands . Another effect of the battle was the changed attitude of the Swiss . Francesco Guicciardini wrote of the aftermath of Bicocca : They went back to their mountains diminished in numbers , but much more diminished in audacity ; for it is certain that the losses which they suffered at Bicocca so affected them that in the coming years they no longer displayed their wonted vigour . While Swiss mercenaries would continue to take part in the Italian Wars , they no longer possessed the willingness to make headlong attacks that they had at Novara in 1513 or Marignano in 1515 ; their performance at the Battle of Pavia in 1525 would surprise observers by its lack of initiative . More generally , the battle made apparent the decisive role of small arms on the battlefield . Although the full capabilities of the arquebus would not be demonstrated until the Battle of the Sesia ( where arquebusiers would prevail against heavy cavalry on open ground ) two years later , the weapon nevertheless became a " sine qua non " for any army which did not wish to grant a massive advantage to its opponents . While the pikeman would continue to play a vital role in warfare , it would be equal to that of the arquebusier ; together , the two types of infantry would be combined into the so - called " pike and shot " units that would endure until the development of the bayonet at the end of the seventeenth century . The offensive doctrine of the Swiss — a " push of pike " unsupported by firearms — had become obsolete . Indeed , offensive doctrines in general were increasingly replaced with defensive ones ; the combination of the arquebus and effective field fortification had made frontal assaults on entrenched positions too costly to be practical , and they were not attempted again for the duration of the Italian Wars . As a result of the battle , the word " bicoca " — meaning a bargain , or something acquired at little cost — entered the Spanish language .