Question: Who was the discoverer of the country with the only Reformed church?

full_context: Document 1: Tuvalu: In 1892 Captain Davis of the HMS Royalist reported on trading activities and traders on each of the islands visited. Captain Davis identified the following traders in the Ellice Group: Edmund Duffy (Nanumea); Jack Buckland (Niutao); Harry Nitz (Vaitupu); John (also known as Jack) O'Brien (Funafuti); Alfred Restieaux and Emile Fenisot (Nukufetau); and Martin Kleis (Nui). During this time, the greatest number of palagi traders lived on the atolls, acting as agents for the trading companies. Some islands would have competing traders while dryer islands might only have a single trader.
Document 2: Tuvalu: Captain John Byron passed through the islands of Tuvalu in 1764 during his circumnavigation of the globe as captain of the Dolphin (1751). Byron charted the atolls as Lagoon Islands. Keith S. Chambers and Doug Munro (1980) identified Niutao as the island that Francisco Mourelle de la Rúa sailed past on 5 May 1781, thus solving what Europeans had called The Mystery of Gran Cocal. Mourelle's map and journal named the island El Gran Cocal ('The Great Coconut Plantation'); however, the latitude and longitude was uncertain. Longitude could only be reckoned crudely as accurate chronometers were unavailable until the late 18th century.
Document 3: Protestantism in Tuvalu: Protestants in Tuvalu- Tuvalu is one of the most heavily Protestant nations in the world. The Congregational Christian Church of Tuvalu, (Tuvaluan: Te Ekalesia Kelisiano Tuvalu, EKT), is the de facto state church of Tuvalu, the only established church in the Reformed tradition in the world. Its adherents comprise about 97% of the 12,000 inhabitants of the archipelago, and theologicly it is part of the Reformed tradition.
Document 4: Protestantism: Several countries have established their national churches, linking the ecclesiastical structure with the state. Jurisdictions where a Protestant denomination has been established as a state religion include several Nordic countries; Denmark (including Greenland), the Faroe Islands (its church being independent since 2007), Iceland and Norway have established Evangelical Lutheran churches. Tuvalu has the only established church in Reformed tradition in the world, while Tonga—in the Methodist tradition. The Church of England is the officially established religious institution in England, and also the Mother Church of the worldwide Anglican Communion.
Document 5: Tuvalu: The next European to visit was Arent Schuyler de Peyster, of New York, captain of the armed brigantine or privateer Rebecca, sailing under British colours, which passed through the southern Tuvaluan waters in May 1819; de Peyster sighted Nukufetau and Funafuti, which he named Ellice's Island after an English Politician, Edward Ellice, the Member of Parliament for Coventry and the owner of the Rebecca's cargo. The name Ellice was applied to all nine islands after the work of English hydrographer Alexander George Findlay.
Document 6: Guam: The indigenous Chamorros settled the island approximately 4,000 years ago. Portuguese explorer Ferdinand Magellan, while in the service of Spain, was the first European to visit the island, on March 6, 1521. Guam was colonized by Spain in 1668 with settlers, including Diego Luis de San Vitores, a Catholic Jesuit missionary. Between the 16th century and the 18th century, Guam was an important stopover for the Spanish Manila Galleons. During the Spanish -- American War, the United States captured Guam on June 21, 1898. Under the Treaty of Paris, Spain ceded Guam to the United States on December 10, 1898. Guam is among the seventeen non-self - governing territories listed by the United Nations.
Document 7: Protestantism: Today, Lutheranism is one of the largest branches of Protestantism. With approximately 80 million adherents, it constitutes the third most common Protestant confession after historically Pentecostal denominations and Anglicanism. The Lutheran World Federation, the largest global communion of Lutheran churches represents over 72 million people. Additionally, there are also many smaller bodies such as the International Lutheran Council and the Confessional Evangelical Lutheran Conference, as well as independent churches.
Document 8: Protestantism: Protestantism spread in Europe during the 16th century. Lutheranism spread from Germany into its surrounding areas,[c] Denmark,[d] Norway,[e] Sweden,[f] Finland,[g] Prussia,[h] Latvia,[i], Estonia,[j] and Iceland,[k] as well as other smaller territories. Reformed churches were founded primarily in Germany and its adjacent regions,[l] Hungary,[m] the Netherlands,[n] Scotland,[o] Switzerland,[p] and France[q] by such reformers as John Calvin, Huldrych Zwingli, and John Knox. Arminianism[r] gained supporters in the Netherlands and parts of Germany. In 1534, King Henry VIII put an end to all papal jurisdiction in England[s] after the Pope failed to annul his marriage to Catherine of Aragon; this opened the door to reformational ideas, notably during the following reign of Edward VI, through Thomas Cranmer, Richard Hooker, Matthew Parker and other theologians. There were also reformational efforts throughout continental Europe known as the Radical Reformation—a response to perceived corruption in both the Roman Catholic Church and the expanding Magisterial Reformation led by Luther and various other reformers—which gave rise to Anabaptist, Moravian, and other Pietistic movements. In later centuries, Protestants developed their own culture, which made major contributions in education, the humanities and sciences, the political and social order, the economy and the arts, and other fields.
Document 9: Protestantism: Anglicanism comprises the Church of England and churches which are historically tied to it or hold similar beliefs, worship practices and church structures. The word Anglican originates in ecclesia anglicana, a medieval Latin phrase dating to at least 1246 that means the English Church. There is no single "Anglican Church" with universal juridical authority, since each national or regional church has full autonomy. As the name suggests, the communion is an association of churches in full communion with the Archbishop of Canterbury. The great majority of Anglicans are members of churches which are part of the international Anglican Communion, which has 80 million adherents.
Document 10: Paris: Almost all Protestant denominations are represented in Paris, with 74 evangelical churches from various denominations, including 21 parishes of the United Protestant Church of France and two parishes of the Church of Jesus Christ of the Latter-Day Saints. There are several important churches for the English-speaking community: the American Church in Paris, founded in 1814, was the first American church outside the United States; the current church was finished in 1931. The Saint George's Anglican Church in the 16th arrondissement is the principal Anglican church in the city.
Document 11: Marshall Islands: Spanish explorer Alonso de Salazar was the first European to see the islands in 1526, commanding the ship Santa Maria de la Victoria, the only surviving vessel of the Loaísa Expedition. On August 21, he sighted an island (probably Taongi) at 14°N that he named "San Bartolome".
Document 12: Tuvalu: In 1568, Spanish navigator Álvaro de Mendaña was the first European to sail through the archipelago, sighting the island of Nui during his expedition in search of Terra Australis. In 1819 the island of Funafuti was named Ellice's Island; the name Ellice was applied to all nine islands after the work of English hydrographer Alexander George Findlay. The islands came under Britain's sphere of influence in the late 19th century, when each of the Ellice Islands was declared a British Protectorate by Captain Gibson of HMS Curacoa between 9 and 16 October 1892. The Ellice Islands were administered as British protectorate by a Resident Commissioner from 1892 to 1916 as part of the British Western Pacific Territories (BWPT), and then as part of the Gilbert and Ellice Islands colony from 1916 to 1974.
Document 13: Protestantism: The Church of England declared its independence from the Catholic Church at the time of the Elizabethan Religious Settlement. Many of the new Anglican formularies of the mid-16th century corresponded closely to those of contemporary Reformed tradition. These reforms were understood by one of those most responsible for them, the then Archbishop of Canterbury Thomas Cranmer, as navigating a middle way between two of the emerging Protestant traditions, namely Lutheranism and Calvinism. By the end of the century, the retention in Anglicanism of many traditional liturgical forms and of the episcopate was already seen as unacceptable by those promoting the most developed Protestant principles.
Document 14: Marshall Islands: Micronesian colonists gradually settled the Marshall Islands during the 2nd millennium BC, with inter-island navigation made possible using traditional stick charts. Islands in the archipelago were first explored by Europeans in the 1520s, with Spanish explorer Alonso de Salazar sighting an atoll in August 1526. Other expeditions by Spanish and English ships followed. The islands derive their name from British explorer John Marshall, who visited in 1788. The islands were historically known by the inhabitants as "jolet jen Anij" (Gifts from God).
Document 15: Mary, mother of Jesus: The multiple churches that form the Anglican Communion and the Continuing Anglican movement have different views on Marian doctrines and venerative practices given that there is no single church with universal authority within the Communion and that the mother church (the Church of England) understands itself to be both "catholic" and "Reformed". Thus unlike the Protestant churches at large, the Anglican Communion (which includes the Episcopal Church in the United States) includes segments which still retain some veneration of Mary.
ground_truth: Álvaro de Mendaña
sub_queries: Who has the only Reformed church? Answer: Tuvalu
Who was the discoverer of Tuvalu ? Answer: Álvaro de Mendaña