Ireland is a country in northwestern Europe located in the North Atlantic Ocean. The North Channel, the Irish Sea, and St George's Channel divide it from Great Britain to the east. Ireland is the second-largest island in the British Isles, the third-largest island in Europe, and the twentieth-largest island on the planet.
Ireland is split geopolitically between the Republic of Ireland (formally known as Ireland), which encompasses five-sixths of the island, and Northern Ireland, which is part of the United Kingdom. Ireland's population was around 6.6 million in 2011, making it the second-most populated island in Europe after Great Britain. In 2016, the Republic of Ireland had 4.8 million residents, while Northern Ireland had 1.8 million.
Ireland's landscape consists of low-lying mountains around a core plain with many navigable rivers spreading inland. Its luxuriant vegetation is a result of its warm but fluctuating environment, which is devoid of temperature extremes. Until the end of the Middle Ages, most of Ireland was covered in forest. Today, forest covers around 10% of the island, compared to a European average of over 33%, and the majority of it is non-native conifer plantations. Ireland is home to twenty-six extant terrestrial mammal species. The Irish climate is affected by the Atlantic Ocean and consequently quite warm, with winters milder than anticipated for such a northerly location, but summers cooler than in continental Europe. There is a lot of rain and cloud cover.
By the first century AD, Gaelic Ireland had evolved. From the fifth century forward, the island was Christianized. Following the Anglo-Norman conquest in the 12th century, England claimed dominion. However, the English administration did not reach the whole island until the 16th–17th century Tudor invasion, which resulted in colonization by the British people. A system of Protestant English control was established in the 1690s to significantly disadvantage the Catholic majority and Protestant dissidents, and it was expanded throughout the 18th century. Ireland became a member of the United Kingdom with the Acts of Union in 1801. Following a war of independence in the early twentieth century, the island was partitioned, resulting in the Irish Free State, which grew more autonomous during the following decades, and Northern Ireland, which remained a member of the United Kingdom. From the late 1960s until the 1990s, Northern Ireland saw significant civil upheaval. Following the Good Friday Agreement in 1998, this subsided. The Republic of Ireland joined the European Economic Community in 1973, together with the United Kingdom and Northern Ireland. The United Kingdom, including Northern Ireland, departed what was then the European Union in 2020. (EU).
Irish culture has had a profound impact on other civilizations, particularly in literature. A significant indigenous culture persists alongside mainstream Western society, as exhibited via Gaelic sports, Irish music, Irish language, and Irish dance. Many aspects of the island's culture are similar to those of the United Kingdom, including the English language and sports like as association football, rugby, horse racing, golf, and boxing.