European influence in Paraguay began with the early explorations of the Río de la Plata. Juan Díaz de Solís was the first to come (1516), and Sebastian Cabot followed him (1527) to the Paraguay River, which was thought to offer access to Peru. One of the main reasons for the voyages (c.1535) of Juan de Ayolas and Domingo Martínez de Irala was to seek a way across the continent. A colony grew up, as Asunción became the nucleus of the La Plata region. Irala dominated the colony until his death (1556 or 1557) and clashed with Álvar Núñez Cabeza de Vaca.
At the end of the 16th cent. Hernando Arias de Saavedra, called Hernandarias, became governor of Río de la Plata prov., of which Paraguay was a part; it was through his efforts that the administrations of present Argentina and Paraguay were separated (1617). The Jesuit missions were founded in the days of Hernandarias (most of them in the trans-Paraná area, now in Argentina). Real independence from Spain was asserted when in 1721 José de Antequera led the comuneros of Asunción in a successful revolt and governed independently for some 10 years. In 1776 the region was made part of the viceroyalty of the Río de la Plata.
Manuel Belgrano was unsuccessful in carrying the Argentinean revolution against Spain into Paraguay in 1810, but the next year the colonial officials there were quietly overthrown. In 1814 the first of the three great dictators who were to mold Paraguay came to power. He was José Gaspar Rodríguez Francia, the incorruptible, harsh, and autocratic dictator known as El Supremo, who kept Paraguay in the palm of his hand until his death in 1840. He was succeeded by another dictator, Carlos Antonio López, who held absolute power from 1844 to 1862. His son, Francisco Solano López, succeeded him and brought on disaster by involving Paraguay in war with Brazil, Argentina, and Uruguay (1865–70; see Triple Alliance, War of the). The Paraguayans fought heroically and sustained the loss of more than half the population.
Recovery from the catastrophic war was slow, and the desperate state of the economy was matched by political confusion, as warring caudillos established short-lived dictatorships. Nevertheless, in the late 19th and early 20th cent. conditions improved. Trade increased as Paraguayan products found markets, immigration was encouraged, and farming and modest little industries prospered fitfully. The unsettled boundary with Bolivia, however, turned from an irritation into a threat, and in 1932 Paraguay plunged into another major war—the Chaco War (see under Gran Chaco), which lasted until 1935. From it the little country emerged victorious but exhausted.
The rapid succession of governments afterward was broken by the years when Higinio Morínigo was in power (1940–48). Signs of recovery from the Chaco War appeared in improvements in education, public health, and roads, but the oppressive dictatorship of Morínigo was challenged by numerous uprisings. He was overthrown in 1948, and the country was again subjected to a series of short-lived governments.
Gen. Alfredo Stroessner engineered a successful coup in 1954 and stayed in power by repeatedly suppressing opposition. He was elected president in 1958 and 1963; the 1967 constitution permitted him to be reelected numerous times. Under his rule the national economy improved and financial relationships with other countries were strengthened. Although Stroessner was elected in 1988 for an eighth term, Paraguayans wearied of his domineering administrative style. He was overthrown in a coup in Feb., 1989. The coup leader, Gen. Andres Rodríguez, was elected president, and he gradually began moving the country away from its authoritarian past.
In 1993, Juan Carlos Wasmosy of the governing Colorado party won the presidency, but his power was weakened by a divided legislature, labor strikes, and the demands of farmers for more equitable land distribution. In Apr., 1996, an apparent military coup by the army chief, Lino Oviedo, was averted. When Oviedo became the presidential candidate of the Colorado party in 1997, however, Wasmosy had him arrested on charges of insubordination in the 1996 dispute. Oviedo was sentenced to 10 years in prison; his running mate, Raúl Cubas Grau, replaced him and won the 1998 election. Wasmosy was later (2002) convicted of corruption because of his role in a bank scandal during his presidency.
Shortly after taking office Cubas freed Oviedo, and later ignored a supreme court order to return the former general to prison. A bitter power struggle developed between Cubas and his vice president, Luis María Argaña, who was killed in a street ambush in Mar., 1999. Following several days of rioting, Cubas was impeached on charges of misuse of public office; he resigned and fled to Brazil, returning in 2002 to face charges arising from the assassination. Oviedo fled to Argentina but disappeared in December, claiming to have returned to Paraguay. The president of the senate, Luis González Macchi, became president, heading a government of national unity.
An attempted coup by supporters of Oviedo failed in May, 2000, and Oviedo was arrested the following month in Brazil. A special vice presidential election in August was narrowly won by the Liberal party candidate, Julio César Franco; it was the first national election lost by the Colorado party since it came to power in 1947. Franco benefited from the split within the Colorado party and had the de facto support of Oviedo.
González Macchi's coalition subsequently disintegrated as his opponents within the Colorado party and Franco's supporters sought to undermine the president. In 2001, Paraguay's request to extradite Oviedo from Brazil was rejected by the latter country's supreme court. Opposition to the president culminated in 2003 in an impeachment trial for corruption that González Macchi denounced as politically motivated; the president survived when his opponents fell short of the two thirds majority needed to convict him in the Paraguayan senate. In the Apr., 2003, presidential election, Óscar Nicanor Duarte Frutos, the Colorado party candidate, won; Franco placed second. Oviedo returned to Paraguay in June, 2004, and was promptly arrested and jailed, but he was released on parole in Sept., 2007, and his conviction was overturned the next month.
In 2006 former president Macchi was convicted of involvement in the illegal transfer in 2000 of Paraguayan central bank funds to the United States. He denied any involvement and blamed the central bank officials who had been convicted in 2004; his conviction was overturned on appeal. He was later convicted (2006) of fraud and embezzlement. Fernando Lugo Méndez, the former Roman Catholic bishop of San Pedro and a moderate leftist who was the candidate of an opposition coalition, was elected president in Apr., 2008, with about 41% of the vote. His victory ended more than six decades of Colorado party rule, but the Congress remained dominated by conservative parties. In September, Lugo accused his predecessor and former General Oviedo of being involved in a plot to overthrow him; they denied the accusation.
In Apr., 2009, Lugo's reputation was damaged when he was forced to acknowledge that he had fathered a child while a bishop. There were accusations that he had additional children with other women, and he eventually acknowledged having a second child. Brazil agreed in 2009 (ratified 2011) to triple payments to Paraguay for exported electricity generated by the Itaipú Dam. In 2010, attacks by leftist guerrillas led in April to the imposition of a 30-day state of emergency and military rule in N Paraguay, but no significant progress against the guerrillas resulted. Lugo, who had alienated both his leftist supporters and more conservative Liberal party allies, lost support in the Congress after a land eviction by police in June, 2012, led to violence and 17 deaths, and he was quickly impeached and removed from office by both his Colorado opponents and former Liberal allies. Federico Franco Gómez, the vice president and a Liberal, succeeded Lugo as president. Mercosur suspended Paraguay for a year in response to the impeachment. Horacio Cartes Jara, a wealthy businessman and the Colorado party candidate, was elected president in Apr., 2013.