Question: What nationality was the leader of the expedition that Juan de Zubileta began on August 10, 1519?

Context paragraphs:
Juan de la Cueva: Juan de la Cueva de Garoza (1543–1612) was a Spanish dramatist and poet.  He was born in Seville to an aristocratic family; his younger brother Claudio, with whom he spent some time in Guadalajara, Mexico, went on to become an archdeacon and inquisitor.  He was acquainted with a number of major contemporary intellectual figures, including Fernando de Herrera and Juan de Mal Lara, and took part in the Casa de Pilatos literary academy in Seville.  After his return to Spain in 1577, he began writing for the stage and produced a total of ten comedies and four tragedies.  He appears never to have married, though some of his poetical works are dedicated to a Felipa de la Paz.  After apparently spending some time in Cuenca after 1610, he died in Granada in 1612.

Juan de Zubileta: Juan de Zubileta was one of the members of Ferdinand Magellan's expedition to circumnavigate the globe, which began in Seville on August 10, 1519.  Zubileta was one of the eighteen men who managed to complete the expedition, reaching Sanlúcar de Barrameda on September 6, 1522 on the "Victoria", along with 17 other survivors.

Juan de Sanct Martín: Juan de Sanct Martín, also known as Juan de San Martín, was a Spanish conquistador.  Little is known about De Sanct Martín, apart from a passage in "El Carnero" (1638) by Juan Rodríguez Freyle and "Epítome de la conquista del Nuevo Reino de Granada", a work of uncertain authorship.  He took part in the expedition from Santa Marta into the Eastern Ranges of the Colombian Andes led by Gonzalo Jiménez de Quesada and founded Cuítiva, Boyacá in 1550.  Juan de Sanct Martín headed the left flank of the Spanish troops in the Battle of Tocarema against the Panche on August 20, 1538, while his fellow conquistador Juan de Céspedes commanded the right flank.  In this battle, Juan de Sanct Martín killed the "cacique" of the Panche and was hurt himself.  Juan de Sanct Martín had confronted the Panche the year before, when he was sent to the west while De Céspedes went south.  Due to the resistance of the bellicose Panche, De Sanct Martín returned to the Spanish camp.

María Izquierdo (artist): María Izquierdo (October 30, 1902, San Juan de los Lagos – December 2, 1955, Mexico City) was a Mexican painter.  She was born María Cenobia Izquierdo Gutiérrez in San Juan de los Lagos in the state of Jalisco;.  After her father died, when she was five years old, she lived with her grandparents and aunt afterward in small towns of Aguascalientes, Torreón, and Saltillo.  Both her grandmother and aunt were devout Catholics and much of her upbringing revolved around daily Catholic traditions.  At age fourteen she had an arranged marriage to a senior army officer, Colonel Cándido Posadas, and bore three children by the time she was 17 years old.  In 1920 she and her family moved to Mexico City from San Juan de los Lagos where she first began to develop into a professional artist.

Victoria (ship): Victoria (or Nao "Victoria, as well as Vittoria") was a Spanish carrack and the first ship to successfully circumnavigate the world.  "Victoria" was part of a Spanish expedition commanded by the Portuguese explorer Ferdinand Magellan, and after his death during the voyage, by Juan Sebastián Elcano.  The expedition began on August 10, 1519 with five ships but "Victoria" was the only ship to complete the voyage, returning on September 6, 1522.  Magellan was killed in the Philippines.  The ship was built at a shipyard in Gipuzkoa, with the Basques being reputed shipbuilders at the time, and along with the four other ships, she was given to Magellan by King Charles I of Spain (The Holy Roman Emperor Charles V).  "Victoria" was named after the church of Santa Maria de la Victoria de Triana, where Magellan took an oath of allegiance to Charles V. "Victoria" was an 85 ton ship with a crew of 42.

Juan de Quevedo: Juan de Quevedo (, c. 1450 – December 24, 1519) was a Spanish Franciscan priest and the first Bishop of Santa María de La Antigua del Darién in Panama (1513-1519).

Battle of Tocarema: The Battle of Tocarema (Spanish: "Batalla de Tocarema") was a battle fought between an alliance of the troops of Spanish conquistador Gonzalo Jiménez de Quesada and "zipa" of the Muisca Sagipa of the southern Muisca Confederation and the indigenous Panche.  The battle took place on the afternoon of August 19 and the morning of August 20, 1538 in the "vereda" Tocarema of Cachipay, Cundinamarca, Colombia and resulted in a victory for the Spanish and Muisca, when captains Juan de Céspedes and Juan de Sanct Martín commanded two flanks of the conquistadors.

Juan de Flandes: Juan de Flandes ("John of Flanders"; c. 1460 – by 1519) was an Early Netherlandish painter who was active in Spain from 1496 to 1519; his actual name is unknown, although an inscription "Juan Astrat" on the back of one work suggests a name such as "Jan van der Straat".  Jan Sallaert, who became a master in Ghent in 1480, has also been suggested.

San Juan de Ulúa: San Juan de Ulúa, also known as Castle of San Juan de Ulúa, is a large complex of fortresses, prisons and one former palace on an island of the same name in the Gulf of Mexico overlooking the seaport of Veracruz, Mexico.  Juan de Grijalva's 1518 expedition named the island.  On Easter Sunday 1519, Hernan Cortés met with Tendile and Pitalpitoque, emissaries from Moctezuma II's Aztec Empire.

Ferdinand Magellan: Ferdinand Magellan ( or ; Portuguese: "Fernão de Magalhães" , ] ; Spanish: "Fernando de Magallanes" , ] ; c. 1480 – 27 April 1521) was a Portuguese explorer who organised the Spanish expedition to the East Indies from 1519 to 1522, resulting in the first circumnavigation of the Earth, completed by Juan Sebastián Elcano.

Supporting paragraphs: Juan de Zubileta Ferdinand Magellan
Answer: Portuguese