But they were essentially a pre-professional army fighting a long way from home against an unaccustomed defence tactic: artillery in prepared, entrenched positions firing a hail of anti-personnel shot.

[28] The emperor then nominated an experienced and prestigious general to lead the Imperial forces in Paraguay: Luís Alves de Lima e Silva, then Marquess of Caxias, by a decree on 10 October 1866.

Dionísio Cerqueira [pt], a Brazilian soldier, later recalled, after having ordered a hole to be dug in his tent, that "as soon as the comrade had reached the bottom, we felt the characteristic smell of death.

[46] Another issue was the general lack of materiel: the cavalry was short of horses and those it had were poorly fed;[47] the 2nd Army Corps, for example, was completely dismounted;[46] many soldiers had traded their uniforms and walked half-naked or barefoot; the Minié rifles used by the infantry needed a ramrod to function, many of which had been damaged; the artillery lacked heavy calibre guns, something that some observers pointed out as one of the causes for the allied defeat at Curupayty; there were also no ox carts or oxen to transport goods and troops.

[55] He took several months to reorganise and stabilise the front before deciding to resume allied actions; this made him a subject of mockery and criticism in the Brazilian press, which did not understand the issues surrounding the theatre of war.

[45] A medical commission led by Francisco Pinheiro Guimarães, a physician and colonel of Voluntários da Pátria who had already dealt with epidemics in Brazil, was nominated by Caxias to inspect the hospitals.

[66] In addition, Caxias was also concerned with the tactics and procedures adopted by the troops in battle; he banned the use of any occupation badges in combat and reconnaissance missions, ordering the officers' kepi to be covered with a white tissue, similar to what the soldiers used; this demonstrated his willingness to set aside the old aristocratic pageantry if it interfered with the war.

[66] An intense movement of provisions took place, with horses and mules being bought to be used in combat and in the transport of goods; the animals began to be fed alfalfa and corn, proper food that prevented them from falling ill.[68] Caxias took fourteen months to implement these measures.

The traveller Sir Richard Burton visited a Brazilian camp near Humaitá in August 1868 and was impressed by its hygienic cleanliness and how well the soldiers were sheltered, clothed and fed.

Brazilian troops, artillery, ammunition and stores had to be brought to the vicinity of Humaitá from Rio de Janeiro by steamship: a 1,500 nautical mile (2,778 km) journey down the Atlantic ocean and up again through the rivers Plate, Paraná and Paraguay that took about a fortnight.

[93] As to the strength of such defences, cadets at West Point were taught general Horatio Gouverneur Wright's maxim: "A well intrenched line, defended by two ranks[94] of infantry cannot be carried by a direct attack".

"Until 1865, the Brazilian army was essentially pre-professional", wrote American scholar William S. Dudley: its officer corps did not awaken to the need for modernisation and renewal until after the war.

Richard Burton saw and described them; The rough contrivance, varying from forty to sixty feet in height, is composed of four or more thin tree-trunks, planted perpendicularly, and supplied with platforms or stages of cross-pieces, mostly palms, the whole being bound together with the inevitable raw hide.

[101]In August 1866 the Polish engineer Robert Adolf Chodasiewicz [pl] of the Argentine army, who had acquired his skills in the Crimean War, had made a preliminary map of the area south of Humaitá; he did so by triangulating from three mangrullos.

These were very unreliable, and usually failed to go off on target, but as Burton remarked "even disciplined men feel a natural horror of, and are easily demoralized by, hidden mysterious dangers so swiftly and completely destructive".

[141] Indeed it has been argued that the Paraguayan war was only part of a broader conflict in Spanish America: "a struggle for mastery between the modernizing factions led by presidents Mitre and Sarmiento in Buenos Aires, who wanted to develop links with European capitalism and a world market, and the conservative opposition represented by Paraguay, the blancos of Uruguay, and the federalists of Argentina, who wished to cling to a traditional way of life".

Many of the soldiers are in a state bordering on nudity, having only a piece of tanned leather round their loins, a ragged shirt, and a poncho made of vegetable fibre... A great part of them are still armed with flint guns.

[150] Several months after Curupayty, after being reinforced with an additional twenty thousand men of the newly created 3rd Army Corps, under the command of Manuel Luís Osório, and containing the cholera epidemic, Caxias finally resumed operations.

The Argentine contingent crossed the south arm by a pass that had been discovered by the scouts; owing to some misunderstanding the Brazilians continued to march on beside the southern edge of the marsh and encountered soggy ground, which made for slow going.

[184] The ironclads were trapped between Curupayty and Humaitá for some months, but they were able to manoeuvre, and their gunfire sank the pontoons on which the great chain boom rested, sending it to the bottom of the river.

On 1 November, López, fearing the allies would place a battery at Tayí and interdict his shipping, sent a steamer with George Thompson to mark out a trench and a force of infantry and artillery to defend it.

[202][203] To coincide with the diversionary attack it was decided to capture a redoubt or small earthwork fort about 3,500 yards north of Humaitá, called "Estabelecimento novo" (by the Brazilians) or "Cierva" (by the Paraguayans).

Its skipper positioned it between Cabral and Lima Barros despite the danger of collision due to the pitch black night, and its crew opened a fire of grapeshot against the Paraguayans.

[212][213] Thus, having failed to capture an ironclad, López left Humaitá on the night of 3 March 1868 with twelve thousand of his soldiers;[209][214] he crossed the Paraguay River to Timbó, on the Chaco side.

[219] "Had the naval commanders left even one ironclad between Timbó and the fortress, its guns could have prevented López from escaping through the Chaco brush", wrote Whigham, but they "forgot" to plug the gap.

[231][232] The remaining Paraguayan garrison at the fortress did not fire back, which made Caxias believe it was empty; thus, he ordered Osório's 3rd Army Corps to reconnoitre and take the place by storm.

The flags of all nations waved over board huts, mat hovels, and canvas tents, which, foul in the extreme, formed a hollow square round a pool of filthy water.

There were even bed and breakfasts with ambitious names like Hôtel Français.In the unclean lines which represented streets, idle ruffians were lounging about, drunken cut-throats gave ear to guitar or accordion, and everywhere, on foot and on horseback, appeared the petticoats and the riding-habits of an unmistakable calling.

[251] Thus, when Brazil, Argentina and Uruguay signed the Treaty of the Triple Alliance against Paraguay, their military agreed that the destruction of Humaitá should be the principal object of the war, to which every other consideration must be subordinated.

[261] "The camp appeared clean in the extreme, owing to the stringent orders of Marshal Caxias, who well knows that cholera is to be prevented by drainage, and that water impregnated with sewage and decay breeds fever.