The 9th Military Region (, 9.ª RM) is an administrative command of the Brazilian Army based in Campo Grande, Mato Grosso do Sul, with jurisdiction over that state and Mato Grosso. It corresponds to the area of the Western Military Command, to which the region is subordinated, currently tasked with personnel management and oversight responsibilities.
The states under its jurisdiction originated as a distant, militarized frontier during the colonial period, with demographic development beginning around bases and fortifications along the Paraguay and Guaporé rivers. The Arms Government of the province of Mato Grosso, established in 1821, is considered the precursor of the modern Military Region. After the Paraguayan invasion (1864–1868), the province became the third-largest military contingent in the Empire of Brazil. However, in the early decades of the First Brazilian Republic, military service in Mato Grosso was stigmatized; it was a region with poor accessibility and harsh working conditions, often used as a transfer destination for dissenters and "incorrigibles". Military personnel serving there were typically outsiders.
On the other hand, officers in Mato Grosso held significant social, economic, and political influence, often participating in the frequent armed struggles for the state government during Brazil's early republican period. The regional command underwent several reorganizations, becoming the 7th Military District (1891), the 13th Military Region (1908), the Military Circumscription of Mato Grosso (1915), the 1st Military Circumscription (1919), and finally the 9th Military Region (1934). The arrival of the Northwest Brazil Railway in the southern part of the state (which was not yet separated from the northern part) in 1914 improved transportation but did not eliminate the logistical challenges. However, it prompted the transfer of the headquarters to its current location, Campo Grande, in 1919. The southern part of the state then became the primary concentration of troops.
In the 1920s, Mato Grosso was a focal point of tenentist conspiracies, and in the following decade, it became an important theater of operations during the Constitutionalist Revolution of 1932. From 1946 to 1985, the Military Region was subordinated to the Central Military Zone/II Army, based in São Paulo. The brigades and divisions created in Mato Grosso were not subordinated to the 9th Military Region, which currently does not command combat units.
History Early years and control of the rivers
The military presence and occupation of the borders have shaped the history of Mato Grosso and Mato Grosso do Sul since the establishment of the Captaincy of Mato Grosso in the mid-18th century. Rivaling the Spanish Empire for dominance over the heart of South America, the Overseas Council of the Portuguese Empire created the captaincy in 1748 to make the "colony of Mato Grosso so powerful so that it imposes respect in its neighbors and serves as a bulwark for the entire interior of Brazil". The first Portuguese governor, Antônio Rolim de Moura, arrived in 1751 with an infantry regiment, officers, artillery pieces, and ammunition. His administration focused on fortifying the border along the Guaporé River, in present-day Mato Grosso and Rondônia, through which the captaincy communicated with the Court. In 1771, captain Luís de Albuquerque de Melo Pereira e Cáceres of the Portuguese Army assumed the governorship. His name is honored in the 9th Military Region with the title "Mello e Cáceres Region".
The territory was vast and sparsely populated. The local economy, centered on mining, was very poor, relying on external supplies of tools, weapons, ammunition, and even food. Internal communications were precarious, and these challenges persisted for many decades.
Navigation to Mato Grosso was facilitated by the Paraguay River, whose outlet to the River Plate was controlled by the Spanish. However, the Spanish advance upstream from Asunción was halted by the construction of Fort Coimbra in 1775. Located at a narrow, easily defensible point, the fort gave the Portuguese control over both banks of the river. Additional fortifications and settlements consolidated Portuguese possession of the right bank. This would become Mato Grosso's first line of defense against an invasion via river. The Miranda Presidio, built in 1797, blocked Spanish progress along the Apa River. The forts, outposts, presidios, and military colonies established along Mato Grosso's borders later became the founding nuclei of many settlements.
Paraguayan War
After the independence of South American colonies, Mato Grosso remained strategically important to Brazil as a buffer zone between the country's central provinces (Minas Gerais, São Paulo, and Rio de Janeiro) and the influences of the Platine region (Argentina, Paraguay, and Bolivia). However, by the mid-19th century, the province was one of the weakest in the Empire of Brazil, with a declining economy and population, making it a target for the ambitions of the Republic of Paraguay. In 1863, its defenses comprised only 1,415 regular soldiers (excluding the National Guard), organized into the 2nd Foot Artillery Battalion, Artillery Corps, Cavalry Corps, Hunters Battalion, and Craftsmen Company. Military authority was vested in the Arms Government (later Arms Command) of the province of Mato Grosso, created in 1821 and considered the precursor to the modern Military Region. This institution was subordinated to the provincial president.
Paraguayan troops found it relatively easy to invade Mato Grosso in 1864, initiating the Paraguayan War. The Mato Grosso campaign was fought in the southern part of the province and was marked by the floods of the Pantanal, as well as hunger and disease, which exacted a heavy toll on the troops. Contemporary observers and historians often highlighted the element of surprise and the unpreparedness of Mato Grosso's defenses. However, historian Mário Maestri argued that authorities had been warned in advance, there were considerable stockpiles of arms and ammunition, and the local force could have reached 6,000 troops if the National Guard was mobilized. According to him, the defensive weakness stemmed from the population's unwillingness to volunteer.
The Paraguayan offensive followed a riverine axis, capturing Fort Coimbra and the towns of Albuquerque and Corumbá, and a land axis targeting the military colonies along the Miranda and Dourados Rivers and the towns of Nioaque, Miranda, and Taquari. Despite fears of a deeper invasion, the Paraguayans never reached the provincial capital, Cuiabá. Reinforcements for the Brazilian forces came from other provinces, such as São Paulo and Minas Gerais. A Brazilian attempt to invade Paraguayan territory led to heavy losses during the Retreat from Laguna. Corumbá was temporarily retaken by Brazilian forces in 1867 and permanently in 1868, as the Paraguayans abandoned their military occupation of Mato Grosso. This withdrawal was prompted by their setbacks on another front of the war, Humaitá, which opened Paraguayan territory to invasion by the Triple Alliance.
The Mato Grosso campaign was a secondary theater of the war but had a profound impact on the local history. In the following century, battles and figures such as Carlos Camisão, Guia Lopes, and Antônio João were commemorated in monuments, street names, and public buildings, and the campaign was promoted as a cornerstone of Mato Grosso do Sul's identity. After 1870, the Paraguay River was fully opened to international navigation, attracting settlers and investments to the southern part of the province, though the region also saw an increase in foreign bandit activity and land disputes. Fearing Paraguay and Argentina, the Empire of Brazil reinforced military presence in Mato Grosso, with troop numbers fluctuating between 1,237 and 2,481 men between 1871 and 1888. By 1889, the year of the Proclamation of the Republic, Mato Grosso had the third-largest army contingent among Brazilian provinces, representing 5% of the total. Garrisons were stationed in Cuiabá, Cáceres, Nioaque, and Corumbá, also contributing to the occupation of Paraguay, which lasted until 1876.
Beyond international concerns, the army also fought against indigenous raids around Cuiabá and in the Mato Grosso backlands. These operations, combined with the need to protect the Paraguay and Guaporé Rivers with limited resources, scattered the forces across garrisons ranging from 1 to 64 soldiers. By 1884, approximately 25% of the troops served far from their unit headquarters, guarding fortresses, depots, riverbanks, and military colonies. This dispersion hindered both administrative routines and training efforts.
First Brazilian Republic and Military District
The Proclamation of the Republic was met in Mato Grosso with a small monarchist revolt by enlisted soldiers at the detachment on the Apa River's mouth on 20 December 1889. In 1891, the Arms Commands were replaced by Military Districts, subordinated to the Ministry of War, which would form major operational units in wartime. The 6th and 7th Districts, corresponding respectively to Rio Grande do Sul and Mato Grosso, were the only ones covering a single state due to their strategic importance. The district headquarters was in Cuiabá, and the units remained stationed along the rivers of the Paraná Basin. Transportation, whether by river or animal traction, was challenging, especially during droughts. Telegraphic communication with the rest of the country, a geostrategic military necessity, began only in 1891 when Cuiabá was connected to the Goiás border.
Mato Grosso was a demographic void, and most of the military personnel stationed there were from other states. The journey was long, food and accommodations were poor, and diseases ravaged both enlisted men and officers. The region carried the stigmas of being backward, violent, and uncivilized, being described by Euclides da Cunha as the army's "canicular Siberia." Transfer to Mato Grosso was considered a punishment and a career setback. Since the Imperial period, political dissenters were informally transferred there as punishment, contributing to frequent local revolts. In 1907, general Dantas Barreto criticized the "system adopted by all Republican governments of filling the ranks of the federal force there with incorrigible personnel from other garrisons". Officers did everything they could to avoid serving there, and many men, thanks to their connections, never reported for duty.
Between 1860 and 1907, the typical infantry soldier (representing more than half of those recorded in the Record Books) in Mato Grosso was from another state (especially from Northeastern Brazil), of mixed race, standing between 1.60 and 1.69 meters tall, aged 18 to 25, single, without a trade, and illiterate. Recruits from outside the state were often forcibly conscripted (known as the "blood tax") as a way for authorities to rid themselves of certain groups, such as capoeiras from Rio de Janeiro. Others, like refugees from the Northeast's droughts, volunteered for the army as a means of survival. However, in Mato Grosso, soldiers commonly experienced delays of over twelve months in their pay. Relations between enlisted men and officers were often marked by paternalism or, until the 1910s, by crime and disobedience. Criminality was not exclusive to the army, as banditry was endemic in the region. Desertion, on the other hand, was uncommon due to the predominance of non-local recruits.