that, while very different from examples elsewhere, "..."empire" is probably the most convenient term." European arrival and Christianization In the 15th century and again in the 17th, civil war erupted. It was in this context that the first Europeans arrived, beginning with Dutch explorers Willem Schouten and Jacob Le Maire. Between April 21 to 23, 1616 they moored at the Northern Tongan islands "Cocos Island" (Tafahi) and "Traitors Island" (Niuatoputapu), respectively. The kings of both of these islands boarded the ships and Le Maire drew up a list of Niuatoputapu words, a language now extinct. On April 24, 1616, they tried to moor at the "Island of Good Hope" (Niuafo'ou), but a less welcoming reception there made them decide to sail on. On January 21, 1643, the Dutch explorer Abel Tasman was the first European to visit the main island (Tongatapu) and Haapai after rounding Australia and New Zealand while looking for a faster route to Chile. He mapped several islands. Tasman named the island of Tongatapu t’ Eijlandt Amsterdam (Amsterdam Island), because of its abundance of supplies. This name is no longer used except by historians. The most significant impact had the visits of Captain Cook in 1773, 1774, and 1777, followed by the first London missionaries in 1797, and the Wesleyan Methodist Walter Lawry in 1822. Around that time, most Tongans converted en masse to the Wesleyan (Methodist) or Catholic faiths. Other denominations followed, including Pentecostals, Mormons, Seventh-day Adventists, and most recently the Bahá'í faith. The islands were also visited by the Spanish under Francisco Antonio Mourelle in 1781 and Alessandro Malaspina (who unsuccessfully claimed Vavau for Spain) in 1793 and by the French under Marc-Joseph Marion du Fresne in 1772, Jean-François de Galaup, comte de Lapérouse in 1787, Fletcher Christian in 1789 and Antoine Bruni d'Entrecasteaux in 1793. Unification In 1799, the 14th Tui Kanokupolu, Tukuaho was murdered, which sent Tonga into a civil war for fifty years. Finally, the islands were united into a Polynesian kingdom in 1845 by the ambitious young warrior, strategist, and orator Tāufaʻāhau. He held the chiefly title of Tu'i Kanokupolu, but was baptised with the name King George Tupou I. In 1875, with the help of missionary Shirley Baker, he declared Tonga a constitutional monarchy, at which time he emancipated the serfs, enshrined a code of law, land tenure, and freedom of the press, and limited the power of the chiefs.