Cape Breton Island is a rugged and irregularly shaped island on the Atlantic coast of North America, forming part of the Canadian province of Nova Scotia.
The 10,513.1 km2 (4,059.1 sq mi) island accounts for 18.7% of Nova Scotia's total area. Although the island is physically separated from the Nova Scotia peninsula by the Strait of Canso, the 1,385-metre (4,544 ft) long Canso Causeway connects it to mainland Nova Scotia. The island is east-northeast of the mainland with its northern and western coasts fronting on the Gulf of Saint Lawrence with its western coast forming the eastern limits of the Northumberland Strait. The eastern and southern coasts front the Atlantic Ocean with its eastern coast also forming the western limits of the Cabot Strait. Its landmass slopes upward from south to north, culminating in the highlands of its northern cape. A large body of saltwater, the Bras d'Or ("Golden Arm" in French), dominates the island's centre.
The 2021 census counted 134,850 Cape Bretoners, which is approximately 15% of the provincial population. Cape Breton Island has experienced a decline in population of approximately 2.9% since the 2011 census. Approximately 75% of the island's population is in the Cape Breton Regional Municipality, which includes all of Cape Breton County and is often referred to as Industrial Cape Breton.
Cape Breton Island takes its name from its easternmost point, Cape Breton. This may have been named after the Gascon fishing port of Capbreton, but more probably takes its name from the Bretons of northwestern France. A Portuguese mappa mundi of 1516–20 includes the label "terra q(ue) foy descuberta por Bertomes" in the vicinity of the Gulf of St. Lawrence, which means "land discovered by Bretons". The name "Cape Breton" first appears on a map of 1516, as C(abo) dos Bretoes, and became the general name for both the island and the cape toward the end of the 16th century. The Breton origin of the name is not universally accepted, however: William Francis Ganong argued that the Portuguese term Bertomes referred to Englishmen or Britons, and that the name should be interpreted as "Cape of the English".
The indigenous Mi'kmaq name for the island is Unama'ki, which loosely translates to "land of fog".
Cape Breton Island's first residents were likely archaic maritime natives, ancestors of the Mi'kmaq people. These peoples and their progeny inhabited the island (known as Unama'ki) for several thousand years and continue to live there to this day. Their traditional lifestyle centred around hunting and fishing because of the unfavourable agricultural conditions of their maritime home. This ocean-centric lifestyle did, however, make them among the first Indigenous peoples to discover European explorers and sailors fishing in the St. Lawrence Estuary. Italian explorer (sailing for the British crown) John Cabot reportedly visited the island in 1497. However, European histories and maps of the period are of too poor quality to be sure whether Cabot first visited Newfoundland or Cape Breton Island. This discovery is commemorated by Cape Breton's Cabot Trail, and by the Cabot's Landing Historic Site & Provincial Park, near the village of Dingwall.
The local Mi'kmaq peoples began trading with European fishermen when the fishermen began landing in their territories as early as the 1520s. In about 1521–22, the Portuguese under João Álvares Fagundes established a fishing colony on the island. As many as two hundred settlers lived in a village, the name of which is not known, located according to some historians at what is now Ingonish on the island's northeastern peninsula. These fishermen traded with the local population but did not maintain a permanent settlement. This Portuguese colony's fate is unknown, but it is mentioned as late as 1570.
During the Anglo-French War of 1627 to 1629, under King Charles I, the Kirkes took Quebec City, James Stewart, 4th Lord Ochiltree, planted a colony on Unama'ki at Baleine, Nova Scotia, and Alexander's son, William Alexander, 1st Earl of Stirling, established the first incarnation of "New Scotland" at Port Royal (Annapolis Royal). These claims, and larger ideals of European colonization were the first time the island was incorporated as European territory, though it would be several decades later that treaties would actually be signed. However, no copies of these treaties exist.
These Scottish triumphs, which left Cape Sable as the only major French holding in North America, did not last. Charles I's haste to make peace with France on the terms most beneficial to him meant the new North American gains would be bargained away in the Treaty of Saint-Germain-en-Laye, which established which European power had laid claim over the territories.
The French quickly defeated the Scots at Baleine, and established the first European settlements on Île Royale, which is present-day Englishtown (1629) and St. Peter's (1630). These settlements lasted only one generation, until Nicolas Denys left in 1659. The island did not have any European settlers for another fifty years before those communities along with Louisbourg were re-established in 1713, after which point European settlement was permanently established on the island.
Known as Île Royale ('royal island') to the French, the island also saw active settlement by France. After the French ceded their claims to Newfoundland and the Acadian mainland to the British by the Treaty of Utrecht in 1713, the French relocated the population of Plaisance, Newfoundland, to Île Royale and the French garrison was established in the central eastern part at Sainte Anne. As the harbour at Sainte Anne experienced icing problems, it was decided to build a much larger fortification at Louisbourg to improve defences at the entrance to the Gulf of Saint Lawrence and to defend France's fishing fleet on the Grand Banks. The French also built the Louisbourg Lighthouse in 1734, the first lighthouse in Canada and one of the first in North America. In addition to Cape Breton Island, the French colony of Île Royale also included Île Saint-Jean, today called Prince Edward Island, and Les Îles-de-la-Madeleine.
Louisbourg itself was one of the most important commercial and military centres in New France. Louisbourg was captured by New Englanders with British naval assistance in the Siege of Louisbourg (1745) and by British forces in 1758. The French population of Île Royale was deported to France after each siege. While French settlers returned to their homes in Île Royale after the Treaty of Aix-la-Chapelle was signed in 1748, the fortress was demolished after the second siege in 1758. Île Royale remained formally part of New France until it was ceded to Great Britain by the Treaty of Paris in 1763. It was then merged with the adjacent British colony of Nova Scotia (present-day peninsular Nova Scotia and New Brunswick). Acadians who had been expelled from Nova Scotia and Île Royale were permitted to settle in Cape Breton beginning in 1764, and established communities in northwestern Cape Breton, near Chéticamp, and southern Cape Breton, on and near Isle Madame.
Some of the first British-sanctioned settlers on the island following the Seven Years' War were Irish, although upon settlement they merged with local French communities to form a culture rich in music and tradition. From 1763 to 1784, the island was administratively part of the colony of Nova Scotia and was governed from Halifax.
The first permanently settled Scottish community on Cape Breton Island was Judique, settled in 1775 by Michael Mor MacDonald. He spent his first winter using his upside-down boat for shelter, which is reflected in the architecture of the village's Community Centre. He composed a song about the area called "O 's àlainn an t-àite", or "O, Fair is the Place."
During the American Revolution, on 1 November 1776, John Paul Jones, the father of the American Navy, set sail in command of Alfred to free hundreds of American prisoners working in the area's coal mines. Although winter conditions prevented the freeing of the prisoners, the mission did result in the capture of Mellish, a vessel carrying a vital supply of winter clothing intended for John Burgoyne's troops in Canada.