Yo, el Supremo (I, the Supreme) is a fictionalized account of the 19th-century Paraguayan dictator José Gaspar Rodríguez de Francia, who was also known as "Dr. Francia". The book's title derives from the fact that Francia referred to himself as "El Supremo" or "The Supreme." The first in a long line of dictators, The Supreme was a severe, calculating despot. He ruled absolutely from 1814 until his death in 1840, and is a unique figure in Latin American history. The goal of his rule mirrored that of the Jesuits who had ruled Paraguay for much of its history before him: to keep the Paraguayan people and their customs pure by protecting them from the corrupting influence of European and other outside forces. In Yo, el supremo, Roa Bastos is also fundamentally concerned with the power (and the weakness) of writing itself: its plot revolves around the dictator's efforts to uncover who has been forging his signature on a series of pasquinades discovered around the capital, and his relationship with his secretary, Patiño, to whom he dictates his thoughts and orders, but whom he never fully trusts.

Ruy Díaz de Guzmán's Anales del descubrimiento, población y conquista del Río de la Plata, is considered one of the most important antecedents to Roa Bastos' writings. Guzmán, a Paraguayan Explorer of Guaraní and Spanish heritage, wrote extensively about the geography of Paraguay using mythical descriptions of the landscape and the Guaraní language. The most important precursor to Roa Bastos, however, is Rafael Barrett (1876–1910), whose writings incorporated many of the important themes and writings styles that Roa Bastos would later master including: Spanish-Guaraní bilingualism, magic realism, the revision of Paraguayan history, social literature, exploration of collective memory and the universe of poetic symbols. Barrett's essay "Lo que son los yerbales" is a severe critique of the exploitation of workers on yerba mate tea plantations. Roa Bastos spent part of the early 1940s documenting this same issue and there is much speculation about the role of "Lo que son los yerbales" in the creation of his first major novel Hijo de hombre. The Uruguayan Writer Horacio Quiroga is another important predecessor.

Roa Bastos was born in Asunción on June 13, 1917. He spent his childhood in Iturbe, a provincial town in the Guaira region where his father was an administrator on a sugar plantation. It was here, some 200 kilometres (120 mi) to the south of the Paraguayan capital of Asunción, that Roa Bastos learned to speak both Spanish and Guaraní, the language of Paraguay's indigenous people. At the age of ten he was sent to school in Asunción where he stayed with his uncle, Hermenegildo Roa, the liberal bishop of Asunción.

His uncle's extensive personal library provided the young Roa Bastos with his first exposure to the classical Spanish literature of the Baroque and Renaissance traditions that he would imitate in his early poetry throughout the 1930s and 1940s. In addition, his uncle's emphasis on the mystical aspects of classic literature would have a profound Roa Bastos' later writings. His experience of Guaraní social customs and language combined with the traditional Spanish education that he received in Asunción, created a cultural and linguistic duality that would manifest itself in much of Roa Bastos' writing. His rural upbringing also exposed Roa Bastos to the exploitation and oppression of the indigenous and peasant peoples of Paraguay, which would become a prominent theme in his writing.

In 1932 the territorial Chaco War began between Paraguay and Bolivia and continued until 1935. At some point, perhaps as late as 1934, Roa Bastos joined the Paraguayan army as a medical auxiliary. The war would have a profound effect on the Future Writer who said: "when I left for that war I dreamed of purification in the fire of battles." Instead of glory he found "maimed bodies" and "destruction" which left him to question "why two brother countries like Bolivia and Paraguay were massacring each other", and as a consequence Roa Bastos became a pacifist.

Over the course of his career, Roa Bastos received a diversity of honors and distinctions. In 1941 he won the Ateneo Paraguayo Prize for his (unpublished) novel Fulgencio Miranda. This first award was followed by a British Council fellowship for journalism that enabled him to travel to Europe during World War II. In 1959 Roa Bastos won the Losada prize for his first published novel Hijo de hombre. The adaptation of this novel, for which he wrote the screenplay, won best film in the Spanish language and first prize of the Argentine Instituto de Cinematografia the following year. His most prestigious awards were a 1971 John Guggenheim Foundation Fellowship for creative Writers, and in 1989, the Cervantes Prize, an award given by the Spanish government for lifetime achievement, and Spanish language literature's most prestigious prize. Roa Bastos donated most of his prize money to provide easier access to books in Paraguay.

Throughout this eventful period in his life Roa Bastos continued to write and he was considered a poet of the Paraguayan avant garde. In 1942 he published a book of poems in the classic Spanish style, which he titled El Ruiseñor De La Aurora (The Dawn Nightingale), a work he later renounced. He also had plays successfully performed during the 1940s, though they were never published. Of his prolific poetry of the late 1940s only "El naranjal ardiente" (1960; "The Burning Orange Grove") was published.

In 1944 the British Council awarded Roa Bastos a nine-month fellowship for journalism in London. During this time he traveled extensively in Britain, France and Africa and witnessed the devastation of WWII first hand. He served as the El País war correspondent, notably conducting an interview with General Charles de Gaulle after the latter's return to Paris in 1945. Roa Bastos also broadcast Latin American programs at the invitation of the BBC and France's Ministry of Information.

Undoubtedly, Roa Bastos' own experiences played a significant role in his emphasis on human suffering. As a young man he fought in the Chaco war between Bolivia and Paraguay, an event he portrayed in Hijo de hombre. Later he saw the devastation of WWII at first hand in Europe, the violent strife of 1947 in Paraguay, and the rise of the Argentinian military dictatorship in 1976. His collection of short stories published in 1953, El Trueno entre las Hojas, set the stage for Hijo de hombre and Yo, el Supremo with its dark portrayal of devastating political struggle and oppression. Two decades later, Yo, el Supremo was published, providing a prime Example of Roa Bastos' idea of the engaged Writer. It offered an unflattering, fictionalized account of the final thoughts and ramblings of Paraguay's first dictator, at a time when Paraguay was under the stranglehold of a regime that adopted many of the same policies of oppression and isolationism. Roa Bastos was not alone in using literature to engage in contemporary events during the Latin American Boom period. In the 1960s and 1970s, Gabriel Garcia Marquez and others adopted the same approach. Together, these Writers created the Dictator novel genre.

In 1953 the collection of 17 short stories El trueno entre las hojas (1953; Thunder Among the Leaves) was published and circulated internationally, but it was not until the 1960 publication of the novel Hijo de hombre (Son of Man) that Roa Bastos won major critical and popular success. The novel draws on the oppressive history of Paraguay from the rule of Dr. Jose Gaspar de Francia in the early 19th century until the Chaco War in the 1930s. Its multiple narrative perspectives and historical and political themes anticipate his most famous work, Yo, el Supremo, written more than a decade later. Roa Bastos adapted Hijo de hombre into an award-winning film in the same year as its publication.

The novel itself is "an exceptional cultural phenomenon." It has been suggested that it "[is] more immediately and unanimously acclaimed than any novel since One Hundred Years of Solitude, [and the] strictly historical importance [may] be even greater than that of García Márquez's fabulously successful creation." Yo, el supremo has contributed widely to a number of different genres and styles. It belongs to the genre of novelas de dictadores or dictator novels, and also to the Latin American Boom, a literary movement of the 1960s and 1970s. Yo, el supremo is also an important milestone in the evolution of the historical novel genre. "Yo, el supremo weaves a plethora of formats into a single work: history, novel, sociological essay, moral philosophy, biographical novel, revolutionary pamphlet, testimonial documentary, poetic prose, autobiographic confession, ideological debate over literary limits, and linguistic treatise on the limits of Verbal expression."

The writing of Roa Bastos spans four countries, six decades, and countless genres. In his lifetime he made important contributions to Latin American Boom writing, to the related Dictator Novel, and to the Nuevo Cine film movement through screenplays like Alias Gardelito (1961). Roa Bastos' influence can be found in the works of many foreign post-boom Writers, including Mempo Giardinelli, Isabel Allende, Eraclio Zepeda, Antonio Skármeta, Saul Ibargoyen, and Luisa Valenzuela. The most important author to come out of Paraguay, he also remains highly influential for a new generation of Paraguayan authors. Roa Bastos' relationship with his country, unbroken by over 40 years of exile, was considered so important that in 1989 he was invited back by Paraguay's new President, Andrés Rodríguez, following the collapse of the Stroessner regime.

In Toulouse Roa Bastos taught Guaraní and Spanish literature at the University of Toulouse. Although he had been allowed to visit Paraguay to work with a new generation of Paraguayan Writers, starting in 1970, he was again barred from entry in 1982, for purportedly engaging in subversive activities. There is however, little evidence that he participated in sectarian politics of any kind. In France, Roa Bastos faced the second forced relocation of his life, but he also won a new readership for his work during this time. Helen Lane's English translation of Yo, el Supremo, I, The Supreme, published in 1986, was greeted with widespread acclaim in the English-speaking world. However, in France, Roa Bastos' writing focus was primarily academic, and his literary output did not match that of his time in Argentina. In 1985 Roa Bastos left his post at the University of Toulouse. Following the downfall of the oppressive Alfredo Stroessner regime in 1989, Roa Bastos returned to Paraguay at the request of its new leader Andrés Rodríguez.

Following the toppling of the Stroessner regime, Roa Bastos won the Premio Cervantes (Cervantes Prize), awarded by the Spanish Royal Academy in partnership with the Spanish government, in recognition of his outstanding contributions to Spanish-language literature. It was at this time that Roa Bastos began to travel frequently between Paraguay and France. In 1991, representing Paraguay, Roa Bastos signed The Morelia Declaration "demanding the Reversal of the ecological destruction of the planet." It was at this time that Roa Bastos again became an active Novelist and Screenwriter.

His writing deploys symbols and multiple narratives that build on the collective memory of the Paraguayan people. Hijo de hombre, for Example, constructs an "alternative history of popular movements" out of the people's recollections and symbols. The intertextual novel Yo, el Supremo is particularly representative of this technique, both in its construction and narrative. In El Fiscal (1993), a third novel about the abuses of political power—this time focusing on Stroessner's régime—Roa Bastos again offers an alternative to the accepted versions of events in Paraguay and challenges "the intelligibility of history". To this end he weaves elements of fantasy and metafiction into his narratives.

In 1991 Roa Bastos adapted Yo, el Supremo for the screen. His first novel since Yo, el Supremo, Vigilia del admirante (1992; Vigil of the Admiral) was published in 1992, and El fiscal (1993; The Prosecutor) the following year. Although neither of his later novels had the impact of his earlier work, El fiscal is considered an important work. Roa Bastos died on April 26, 2005 in Asunción from a heart attack. He was survived by his three children, his third wife, Iris Giménez, and a reputation as one of Latin American's finest Writers.

Roa Bastos believed that it was the role of the Writer to directly engage in the interpretation of both contemporary and historical events. Rather than be the objective "chronicler", he thought the Writer should engage morally with the social problems depicted in the writing. According to Roa Bastos, ”literary activity has come to signify the necessity for facing up to a destiny, the will to enlist in the vital reality of a collectivity, in its true moral context and social structure, in the complex relationships of a contemporary reality – that is to say, by projecting themselves toward a universal world of man.” Thus, one of the major themes in the writing of Roa Bastos is a deep and universal humanism, with a particular focus on suffering

As is customary for most Paraguayans of peasant or working class origins, Roa Bastos learned to speak Spanish and Guaraní from birth. Both Spanish and Guaraní are the official languages of Paraguay (the latter is primarily an oral language). Although Guaraní remains the "popular" language spoken at home and on the "street", Spanish is the language of official Business and of power. The preservation and widespread use of an indigenous language after centuries of European immigration is unique in Latin America, and Guarani remains a symbol of Paraguayan nationalism and an "important vehicle for interpreting the country's reality". This is the legacy of the Jesuits who ruled Paraguay in the 18th century and used Guarani (instead of Spanish or Latin) to spread Christianity throughout Paraguay.

The majority of Roa Bastos' work was written in exile owing to the oppressive political condition of his country, at a time when Paraguay was one of the least culturally, economically, and politically developed countries in Latin America. Thus, much of Roa Bastos' important writing is an attempt to "capture the tragic essence, the 'inner weakness' as well as the inner strength of his country's people." His work reveals an intense preoccupation not only with contemporary Paraguay but with its history, looking back to the beginning of the 19th century and the rule of Dr. Gaspar de Francia (whose life is the focus of Yo, el Supremo). While key historical figures and events interest Roa Bastos, it is the impact of these "socio-historical roots" on "the nature of the masses" that forms the central theme of his literary work.