Marengo

by T E Crowdy

  At 3.00 pm on 11 June, Melas called a meeting of his senior commanders and staff to debate what to do next. It was a lively session. According to Stutterheim, there initially appeared to be two options open to Melas: either defeat Bonaparte in battle or move the army to Genoa and take a defensive position at the foot of the Apennines at Novi, just as Joubert and Moreau had done against them the previous year. According to Stutterheim, some of the participants in this meeting were ‘vehemently shouting’ that risking the outcome of the army and the fate of Italy on a battle was irresponsible. Even if Bonaparte was defeated between the Bormida and Scrivia, the Austrians would still find themselves at a disadvantage. This was very true, and Bonaparte knew it. If defeated, he could retreat back towards Stradella, drawing Duhesme’s troops towards him. There was a split. Many, Stutterheim added, did not know what to say, and offered no solutions, instead preferring to curse Zach for placing the army in this position. Among those cursing Zach was Melas himself. Stutterheim said the commander-in-chief ’s hatred of Zach was now at its peak, although Melas still followed his advice, albeit with great indignation.

  During the meeting, a third alternative was presented by staff officer Major Anton von Volkmann. He urged avoiding an open battle, but instead advised the army should cross the Po at Casale and then recover its communications by crossing the Ticino. If the army set out for Casale on the night of 13/14 June, the infantry could cross first, leaving a rearguard in the citadel to protect the bridge. From there, the infantry would take the Verceilli road, overpowering the French detachments on the way. Meanwhile, the cavalry would leave a strong presence at Alessandria and make a false attack towards Cascina Grossa before withdrawing and rejoining the army. On 15 June, the army would head for Novara, in effect following the route taken by Murat to Milan. The army would split into two columns, one following the Navliglio canal into Milan, screening the right flank of the main column marching on Nerviano with all the train and artillery. A few days more and the army would be reunited with Vukassovich, the lines of communication with the Hereditary Lands would be re-established and Milan would have fallen back into Austrian hands. Moreover, Bonaparte’s communications with Switzerland would be cut. The French would be without provisions, and with all the major fortresses in Piedmont still in Austrian hands, what could they have done? They would have negated Bonaparte’s strategic coup de main and robbed him of a swift, decisive victory. According to staff officer Adam Neipperg, General Hadik in particular insisted ‘with great firmness’ that this plan should be adopted.

  It appears Zach had considered a similar plan, but he wanted to cross the Po at Valenza and march on Pavia. Neipperg believed this plan was inferior and would have been difficult because there was no bridge at Valenza, and two French divisions were believed to be in this area. It would have been very simple for these troops to lock themselves up in Pavia to defend the Ticino. The terrain in this area was extremely swampy, and the fields cut with ditches. The wagons and artillery would have found movement very difficult, as would the cavalry.

  There was an impasse.

  Enter once again the Piedmontese spy, Carlo Gioelli, who now comes to play a crucial role in the drama. Since Casteggio, Gioelli had been to see the First Consul. He returned with news on the French positions and intentions (which were probably fabrications on the part of Bonaparte). The intelligence he provided was summarized as follows:

  ‘The enemy has crossed over 6,000 men at Bosco under General Gardanne. These have attacked FML Ott on the 9th. The whole enemy army crosses the Po at Piacenza on two rafts. They want to attack us here, but the spy believes a column has been sent across the mountains to Novi, which will continue to turn us across the Bormida. No enemy are in Pavia; in Milan only the blockading corps, in Pizzighettone he believes there is nothing.’

  This intelligence appeared to support the proposed crossing of the Po rather than a move on Genoa, via Novi. More importantly, Gioelli revealed to Zach the information Bonaparte had asked him to find. Sometimes, one can gauge an opponent’s intentions and fears from the questions they ask their spies to ascertain. Stutterheim writes:

  ‘A very well-tried spy, dispatched from Turin to Milan, by whom he had repeatedly tried to deceive the French army command, and had also fortunately deceived them in the previous campaign, arrived at the headquarters at Alessandria, sent by Bonaparte himself. He recorded several points, which the consul demanded to know. The three most important were:

  ‘- Will the imperial army cross the Po?

  ‘- Where is Hohenzollern?

  ‘- Has Elsnitz already arrived at the army?’

  Although Zach knew the spy was in contact with Bonaparte, he clearly believed Gioelli’s first loyalty was to the Austrians. Based on this premise, Zach hatched a plan so brilliant he believed it would save the army. From Stutterheim’s first account, we find more details on Bonaparte’s questions. The First Consul wanted to know if the crossing point on the Po would be Valenza or Casale? He also wanted to know Hohenzollern’s route itinerary, if the latter was intending to march out of Genoa and rejoin the army. Clearly, Bonaparte had already foreseen Volkmann’s plan. He had already guessed the Austrians would consider trying to escape him. This could be the First Consul’s undoing.

  Zach instructed Gioelli to tell Bonaparte the battle at Casteggio had struck fear and confusion into the Austrians, and they were preparing to cross the Po, before attempting to fight their way westwards over the Ticino, by way of Pavia. To lend credence to the story, Zach told Gioelli to truthfully report the arrival of Elsnitz at Alessandria. The Austrian quartermaster general also provided Gioelli with a bogus document showing Hohenzollern’s supposed march up from Genoa, arriving at Novi on 13 June and Alessandria on 14 June. Gioelli was to say the Austrian army was still in camp at Alessandria, and still sorting out its baggage. If the French moved quickly, and marched towards Casale via Sale, they could intercept the Austrians as they were in the act of a major river crossing. The imperial army would be totally destroyed.

  If Bonaparte swallowed the bait, Zach would achieve his original goal of drawing the French army out onto the open plain, where the Austrian superiority in cavalry and artillery could be best employed. Zach would pin the French at Sale, and then sweep round behind them with a formidable column of troops. The French would be surrounded and driven into the Po. It was a brilliant plan, one which would prove his own intellectual superiority and put an end to Bonaparte’s reputation as a military great.

  Yet there was a flaw. Gioelli now had two paymasters, and whatever Zach thought, Gioelli could not afford to openly betray either party. Bonaparte had offered Gioelli a substantial sum of money (far more than Zach was paying him), so Gioelli refused to tell the First Consul an outright lie.1 Gioelli told Zach he feared being caught out over this fiction of crossing the Po. Annoyed by the spy’s reluctance, but utterly convinced by the brilliance of his plan, Zach led the spy into an adjoining room and called for Colonel Pemler and Major Hohensinner of the pontoon corps. He ordered them each to take their bridging equipment to Casale and their train to Valenza, and begin the construction of bridges over the Po. Zach made them responsible for the slightest delay in carrying out this order. When the two officers had left, Zach turned to Gioelli and said: ‘If you do not wish to announce our passage over the Po to the French Headquarters, others will now bring this news.’ Of course, Gioelli did not want to lose Zach’s money either, so on receiving the assurance that the Austrians were committing bridging equipment, Gioelli agreed to complete the mission.

  Afterwards, Zach wrote a series of orders confirming the pioneers and pontoon builders needed to begin bridging the Po. He also instructed Major Culoz to take one his battalions of infantry to Casale, leaving that very night. As he wrote these orders, one wonders if it crossed Zach’s mind that Gioelli might betray him? Would the spy deliver again, as at Cuneo, or would the spy’s luck or loyalty finally run out? Stutterheim tells us that in the final days of this campaign, the press
ure had started to tell on the Austrian chief of staff. He was at once the leader of every operation, but did not have the authority or power to give weight to the commands he issued in Melas’ name. He was, Stutterheim said, well aware that battles could be as easily lost by ill-luck as gained, and that if the coming battle was lost, he alone would be blamed. This agonizing responsibility weakened him. His anxiety could not have been eased by his over-reliance on a spy.

  MAP 3: Zach’s deception

  1 – Ott retreats to Alessandria from Voghera via Sale, acting as a lure to draw Bonaparte onto the plain between the Scrivia and Bormida; 2 – fictitious march of Hohenzollern from Genoa; 3 – Austrian escape routes via Casale and/or Valenza.

  On 12 June, preparations began for the great battle ahead. While Zach penned the battle plan, orders were issued for the army to move into a new camp on the western side of Alessandria. This move would take place on the afternoon of 13 June. In the meantime, engineers began working on the decoy bridge at Casale. Major Culoz arrived with four companies of infantry in support, and sent a report that the French on the left bank were believed to have withdrawn to Vercelli. Work also began on the construction of a pontoon bridge across the Bormida fifty paces below the existing boat bridge. A key part of Zach’s plan was to lure Bonaparte onto the plain between the Bormida and the Scrivia. Ott’s troops had therefore been withdrawn from Voghera, across the Scrivia to the village of San Giuliano. O’Reilly had withdrawn along a more northerly route, passing through Sale. On the evening of 12 June, Ott was ordered to withdraw from San Giuliano and to cross the Bormida, to unite with the remainder of the army. O’Reilly was also ordered to withdraw, and to take up a position at the hamlet of Marengo.

  Before uncovering the plans and movements of the First Consul, now is an opportune moment to explore the ground over which the coming engagement would be fought. Although many of the historic buildings survive in our times, agricultural methods, the construction of the railways and modern roads and large industrial sites have changed the appearance of the countryside considerably. It is therefore necessary to reconstruct this region as it would have appeared that fateful summer. The region between Tortona and Alessandria forms a large lowland plain, bordered to the north by the River Po and to the south by the northernmost slopes of the Ligurian Apennines. The eastern and western extents of the plain are formed by rivers draining down from the mountains into the Po: the Bormida and Tanaro to the west, and the Scrivia torrent on the east. In 1800, the plain was dotted with vineyards, orchards, smallholdings, farm buildings, isolated country houses, hamlets and several churches. The main roads were often lined with mulberry trees and hedges. Many of the roads and tracks were raised on banks to prevent them flooding, and the plain was cut with drainage ditches and brooks. At its widest extent, the plain is approximately 16km wide and measures 25km north to south.

  From a strategic point of view, the plain acted as something of a hub for the road network in this part of Italy. The main post road from Turin to Piacenza passed through the centre of the plain, through Alessandria in the west and Tortona in the east. The main road from Genoa came up from the south-east of the plain, branching at Serravalle, from where one could travel northwards to Tortona and join the main road there; or north-west to Novi and Pozzolo Formigaro before joining the main road at Spinetta. The northern routes from the plain in the direction of Pavia converged at the town of Sale. To the north-west of the plain were roads to Valenza and Casale, both of which offered crossing points over the Po. An army in possession of the great plain could theoretically march in whichever direction it chose. Following the main road, the distance from Alessandria to Tortona was approximately 20km in 1800, or five hours’ march for infantry, well within what could be accomplished in a single day. A horse might cover the same distance in less than three hours at a walk, or if well-mounted, half that time at a trot.

  Terrain often dictates the shape of a battle, so it is worth investing time in studying this plain in some detail. In June 1800, a traveller on foot leaving Alessandria by the Tortona Gate and following the main road would find the road edged by a reasonably flat meadow – a perfect space for assembling large bodies of troops, just as Zach planned to use it on 13 June. Just over a kilometre away, the traveller would encounter the Bormida River. The course of this river has changed significantly in two centuries. Whereas now it flows northwards to the Po in a fairly straight course, the French 1810 Dépôt de la Guerre plan drawn by Giraldon shows the Bormida as a substantial, meandering river, with muddy banks, wooded on the left (western) bank.

  The main road crossed the Bormida by a bridge formed from a number of anchored riverboats. On 12 June, this boat bridge was supplemented by a second crossing made from sixteen military pontoons about fifty paces above the main bridge.2 On the east bank, the main road passed through a defensive tête-du-pont (bridgehead) fortification - an earthwork guarding the road and protected after Casteggio by fourteen guns. There was just a single exit from this bridgehead, and the ground in front of the works was marshy and cut with ditches, making it very difficult to approach, except by the main road. After exiting the bridgehead, the main road followed for a short time the course of the Bormida until it met the junction of the Pavia road. At this junction, the traveller could turn left and follow the Pavia road approximately 4km through marshy ground to Castelceriolo, a village which controlled access to several good roads to the north and east of the plain. Shortly after this junction there was another road on the right: a track winding its way southwards to the farm of Stortigliona.

  Further along the main road one encountered the first of many vineyards, this first one extending either side of the road. Described in the French 1810 map as vignes à l’Italien, the traditional method of viticulture was to plant vines amid rows of mulberry trees and then festoon the vines from the trees’ branches. This practice kept the vines raised above the humid soil and better exposed them to the sun. (In more arid and mountainous areas, the vines were kept low in order to absorb the heat from the ground.) The leaves of the mulberry trees were in turn harvested for feeding silkworms – Italian silk being particularly prized by the British market at this time. In between the rows of mulberries, the Piedmontese peasants created small parcels of land for growing vegetables, and these would have small irrigation channels cut around them. At the turn of the eighteenth century, the method of growing vines on rows of poles appears to have been increasingly commonplace. In some parts of northern Italy there was a custom to grow vines on tall willow poles as much as 12ft high. These poles resembled a forest of sort. Lejeune’s 1801 painting of the Battle of Marengo shows rows of knee-high staves being stamped into the ground by advancing troops. Having been the scene of fighting in 1799, and with the general disruption which comes to agriculture from warfare, some of the vineyards on the battlefield may indeed have been very young in June 1800, planted that spring to repair damage and losses of the previous year. Still, the rows of upright and interconnecting stakes would have formed a hindrance to horses and carriages, and may have broken up infantry formations attempting to move across them. The main road afforded a clear route through these impediments, and was therefore a vital military artery.

  A kilometre from the bridgehead, the traveller drew level with the farm of Pederbona to their left (sometimes Pedra Bona in French texts). From this point, looking to the right of the road, the traveller would see the farm of Stortigliona about 900 metres in the distance to the south. These two farms readily lent themselves as strongpoints from which the main road could be dominated. A second field of vines sat behind Pederbona, extending south-west and in front of Stortigliona. Continuing eastwards along the main road for ten more minutes, the traveller would pass through meadows before the village of Marengo came into sight. Maps from the 1770s show a farmhouse complex called Stampina to the left of the road, more or less halfway between Pederbona and Marengo, but no mention of this place is made at the time of the battle, and presumably it had fallen int
o ruin by then.3

  About 300 metres from the village of Marengo, the road cut through the Fontanone brook. The Fontanone formed a key part of the landscape and must be described in some detail. North of the main road, the Fontanone headed in a more or less straight line for 2½km towards Castelceriolo. Passing to the west of this town, the brook looped to the right and then joined the Tanaro towards Montecastello. In the other direction, the Fontanone made a sharp turn westwards, for about 400 metres, then turned southwards again before terminating in the fields towards Cascina Bianca. Half a kilometre north of Marengo, the Cavo del Fontanone brook branches from the main Fontanone and runs parallel to it, creating a second ditch.

  This brook, often simply described as a ditch, formed a boundary between the Bormida and the plain. The two crossing points over this ditch reinforced the strategic importance of Marengo and Castelceriolo. Without possession of either of these two points, the movement of artillery and baggage to or from Alessandria would be extremely problematic. Relatively inconsequential in modern times, the Fontanone presented more of a hazard in 1800. The Austrian Pioneer regimental history records the Fontanone as being an eight-metre wide, swampy marsh with high and steep banks which could only be walked through with difficulty, with water over chest height.4 The French 1810 map shows the Fontanone in front of the Barbotta farm as being surrounded by marshy ground and muddy banks. To the west of the main road, the waters appear to have been shallower, but still substantial, and edged with green plants, aquatic rushes and willow trees. After the heavy rains which preceded the battle, one must not underestimate the difficulty of crossing it.