Rathlin Island (from Irish : Reachlainn ) is an island and civil parish off the coast of County Antrim and the northernmost point of Northern Ireland .
Rathlin is the only inhabited offshore island of Northern Ireland, with a steadily growing population of approximately 150 people, and is the most northerly inhabited island of the island of Ireland . Rathlin Island is 4 miles (6 km) from east to west, and 2.5 miles (4 km) from north to south.
The highest point on the island is Slieveard, 134 meters (440 feet) above sea level. Rathlin is 15.5 miles (25 km) from the Mull of Kintyre , the southern tip of Scotland ‘s Kintyrepeninsula. It is part of the Causeway Coast and Glens region , and is represented by the Rathlin Development & Community Association. 
Rathlin is part of the traditional barony Cary (around the town of Ballycastle ), and the current district Moyle. The island is a civil parish and is subdivided into 22 townlands :
Rathlin with subdivision into townlands
A ferry operated by Rathlin Island Ferry Ltd. connects the main port of the island, Church Bay , with the mainland at Ballycastle, 6 miles (10 km) away. Two ferries operate on the road – the fast foot-passenger-only catamaran Rathlin Express ferry and a purpose built larger ferry, commissioned in May 2017, Spirit of Rathlin , which carries both foot passengers and a small number of vehicles, weather permitting.   Rathlin Island Ferry Ltd. won a six-year contract for the service in 2008 providing a subsidized “lifeline” service.  There is an ongoing investigation on how to transfer the environment and the new owners. 
Rathlin is of prehistoric volcanic origin, having been created as part of the British Tertiary Volcanic Province . 
Rathlin is one of 43 Special Areas of Conservation in Northern Ireland . It is home to tens of Thousands of seabirds , Including common murres , kittiwakes , puffins and razorbills – about thirty bird families in total. It is visited by birdwatchers , with a Royal Society for the Protection of Birds Nature Reserve, Rathlin’s bird colony . The RSPB has also successfully managed natural habitat to facilitate the return of the red-billed chough . Northern Ireland’s only breeding pair of choughscan be seen during the summer months. The cliffs on this island are impressive, standing 70 meters (230 ft) tall. Bruce’s Cave  is named after-Robert the Bruce, Also Known As Robert I of Scotland : it was here Said That He Was to-have seen the legendary spider qui est Described as inspiring Bruce to continue His fight for Scottish independence.  The island is also the northernmost point of the Antrim Coast and Glens Area of Outstanding Natural Beauty . 
In 2008-09 the Maritime and Coastguard Agency of the United Kingdom and the Marine Institute Ireland bathymetric undertooknorth of Antrim, update Admiralty charts (Joint Irish Bathymetric Survey Project). Rathlin Island, a submarine geological features has been identified around the world, including a submerged crater or lake. This suggests the events leading to inundation – subsidence of land or rising water levels – were extremely quick. Marine investigations in the area have also identified anemone species, rediscovered the mussel fan (the UK’s largest and rarest bivalve mollusc – thought to be found in Plymouth Sound and a few sites off the west of Scotland) and a number of shipwreck sites ,  including HMS Drake ,  which was torpedoed and sank just off the island in 1917.
The Malone hoard of polished axes from Tievebulliagh or Rathlin Island
Rathlin was probably known to the Romans, Pliny referring to “Reginia” and Ptolemy to “Rhicina” or “Eggarikenna”. In the 7th century Adomnánmentions “Rechru” and “Rechrea insula”, which may have been early names for Rathlin.  The 11th-century Irish version of the Historia Brittonum states that the Fir Bolg “took possession of Man and other islands besides – Arran, Islay and ‘Racha'” – another possible early variant. 
Rathlin was the site of the first Viking raid on Ireland, according to the Annals of Ulster . The pillaging of the island’s church and burning of its buildings took place in 795 ( The Burning of Reaching by Plunderers and Their Shrines were broken and plundered. )
In 1306, Robert the Bruce sought refuge on Rathlin, owned by the Irish Bissett family . He stayed in Rathlin Castle , originally belonging to their lordship the Glens of Antrim . The Bissetts were disposed of by Rathlin by the English, who were in control of the Earldom of Ulster , for welcoming Bruce. Later, in the 16th century, the island came into the possession of the MacDonnells of Antrim .
Main article: Rathlin Island massacre
Rathlin has been the site of a number of massacres. On an expedition in 1557, Sir Henry Sidney devastated the island. In July 1575, the Earl of Essex feels Francis Drake and John Norreys to confront Scottish refugees on the island, and in the ensuing massacre, hundreds of men, and children of Clan MacDonnell were killed.   Also in 1642, Covenanter Campbell soldiers of the Argyll’s Foot Were Encouraged by Their commanding officer Sir Duncan Campbell of Auchinbreck to kill the local Catholic MacDonalds, near relative of Their arch clan enemy in the Scottish HighlandsClan MacDonald . They threw their scores of MacDonald women over their deaths on rocks below.   The number of victims of this massacre has been as low as one hundred and one thousand and one thousand.
In the later 18th century, kelp production became important, with Rathlin becoming a major center for production. The shoreline is still littered with kilns and storage places. This was a commercial enterprise sponsored by the landlords of the island and involved the entire community. 
A 19th-century British visitor to the island found that they had an unusual form of government where they elected to judge who sat on a “throne of turf”. 
Tourism is now a commercial activity. The island had a population of over one thousand in the 19th century. Its current permanent population is around 125. This is the largest population in the world, with the largest populations. Many visitors come for the day, and the island has 30 beds for overnight visitors. The Boathouse Visitors’ Center at Church Bay is open seven days a week from April to September, with minibus tours and bicycle hire disponible. The island is also popular with scuba divers , who come to explore the many wrecked ships in the surrounding waters.
Richard Branson crashed his hot air balloon into the sea off Rathlin Island in 1987 after his record-breaking cross-Atlantic flight from Maine . [ quote needed ]
On January 29, 2008 the RNLI Portrush lifeboat Katie Hannan grounded after a swell hit its stern on breakwater rocks just outside the harbor on Rathlin while trying to refloat an islander’s RIB . The lifeboat was handed over to a salvage company.  
The world’s first commercial telegraphy link was established by employees of Guglielmo Marconi between East Lighthouse on Rathlin and Kenmara House in Ballycastle on 6 July 1898. 
In July 2013, BT Ireland installed a high-speed wireless broadband pilot project to a number of premises, the first deployment of its kind in the UK or Ireland, ‘ wireless to the cabinet’ to deliver 80Mbs to users. 
Tievebulliagh mountain near Cushendall features a Neolithic stone axis factory, and a similar one is found in Brockley, a cluster of houses within the town of Ballygill Middle, featuring the same porcellanite stone. The island was also settled during the Mesolithic and Neolithic periods. There is an unexcavated Viking vessel in a mound formation.