Lambay Island (), often simply Lambay (, ), is an island in the Irish Sea off the coast of north County Dublin, Ireland. The largest island off the east coast of Ireland, it is offshore from the headland at Portrane, and is the easternmost point of the province of Leinster. Of volcanic origin, it has been inhabited since the prehistoric period and has been the subject of multiple archaeological studies. Lambay has notable populations of seabirds, a range of local fauna, some not found elsewhere in Ireland, and a colony of wallabies, as well as more than 300 plant varieties, and was the subject of major studies of flora and birds, and a major multidisciplinary study of flora and fauna between 1905 and 1907. The island is privately owned by a trust for members of certain branches of the Baring family and managed by the current Baron Revelstoke. It has a very small permanent population and few buildings but hosts some day visitors and short-stay guests, and there is a working farm.
Etymology The name 'Lambay' comes from Old Norse Lamb ey meaning "lamb island". The name probably originated from the practice of sending ewes to the island in Spring so they could lamb in a predator-free environment. A similar place name is Lamba in Shetland.
The Irish name for the island is Reachrainn, which is also the Irish name for Rathlin Island.Rathlin Island. Place Names NI. The coastal settlement of Portrane faces Lambay and its name comes from Port Reachrann, the "port of Reachrainn".
Geography Lambay Island is the largest island off the east coast of Ireland. It covers about . The highest point – a hill known as Knockbane – rises to . The island's high ground lies to the east and aside from Knockbane includes Heath Hill and Tinian Hill, and in the extreme northeast, Pilot's Hill. Steep cliffs lie along the northern, eastern, and southern coasts of the island, while the western side has low-lying land and gentle slopes. Due to the island's topography and exposure to weather, the western shore is where almost all of the island's buildings are located – the Castle, coastguard cottages and guest residences, and the Catholic chapel – as well as the only harbour, while two cottages exist on hillier ground.
The island has eight named bays and a few narrow inlets, and the easternmost point is Lambay Head. The bays are, running counter-clockwise from the harbour, Talbot's Bay, named for a former owner, Carnoon Bay, Bishop's Bay, Sunk Island Bay, Tayleur Bay, Freshwater Bay, Saltpan Bay and Broad Bay. Inlets include Seal Hole. There is a sandy beach by the harbour, and several small rocky strands on the steeper coasts.
Geology The island is of volcanic origin, and its basic geology is Lambay Volcanic Formation, mostly igneous rocks. Bedrock is a mix of andesite, tuff (from volcanic ash) and mudstone, as well as breccia, but there are beds of shales and limestones also, and loamy soil. The andesite, present across the whole area of Lambay, is primarily of the specific type Lambay porphyry.
Hydrology A small number of wells, springs and small streams are fed by aquifers, topped up by rainfall and so varying seasonally. The wells include Trinity Well near the peak of Knockbane, and Raven Well near the central-eastern cliffs; there was also historically a spring near Raven's Well, another near the castle, and a well near Carnoon Bay. A small stream flows down into Carnoon Bay and a slightly larger into Freshwater Bay. There was also a stream to Seal Hole, which at least once had three rivulets meeting, one from Raven Well and two from marshy patches nearby, and finally, there was a flow from the vicinity of the castle to the sea near the harbour.
Demographics The island of Ireland has 258 sometime-inhabited islands but Lambay is one of only five of these which lie off the eastern coast. The Copeland Islands off the coast of County Down are the only other islands off the east coast which remain inhabited as of 2020. The population has ranged from reports of over 140 to as few as 3. The table below reports data on Lambay's population taken from Discover the Islands of Ireland (Alex Ritsema, Collins Press, 1999) and the census of Ireland. Census data in Ireland before 1841 are not considered complete and/or reliable.
Administration and designations Lambay Island forms a townland in the civil parish of Portraine, in the barony of Nethercross, within the modern county of Fingal and in the traditional County Dublin.
For electoral purposes, it is in the electoral division of Donabate, within the Swords ward for local authority polls, and the Dublin Fingal constituency for national elections.
The island, a Natura-2000 site, has both Special Protection Area (SPA) and Special Area of Conservation (SAC) designations, as well as being a pNHA. The island is also wholly enclosed by the Rockabill to Dalkey Island SAC which references reef communities and harbour porpoises.
There are, as of 2020, 26 National Monuments (sites on the Record of Monuments and Places), and one possible site.
Flora and fauna The island was discovered to hold 90 species not seen elsewhere in Ireland, and 5 new to science, when studied in 1905–1906.
Flora The island is home to 308 plant types. However, surveys have found that 33 are invasive species that have arisen as weeds from agriculture or horticulture.
Fauna
The island supports one of the largest seabird colonies in Ireland, with more than 50,000 common guillemots, 5,000 kittiwakes, 3,500 razorbills, 2,500 pairs of herring gulls, as well as smaller numbers of puffins, Manx shearwaters, fulmars, and greylag geese.
North Atlantic sea mammals such as grey seals annually pup on the island. The island has a substantial population of rabbits. Ireland's most common rodent, the brown rat is present, as is Ireland's only self-sustaining long-term population of the black rat, with the presence of the former keeping the numbers of the latter under control.
Rockabill and Lambay islands are the best places in County Dublin to see harbour porpoises.
The island also possesses some uncommon invertebrates – the major survey in 1905-1906 discovered species new to science. Among these were three species of earthworm (including Henlea hibernica), a bristletail (Praemachilis hibernica) and a mite (Trachyuropoda hibernica). The earthworm aspect of the study found 34 species, of which 18 were previously unseen in Ireland, including the three new to science as a whole, and noted that the average size of specimens was smaller than on the mainland by a material amount. A degree of local variation was also noted, and for example, one type was particularly prominent near the Raven's Well.
Domestic and non-native fauna There are also non-native red-necked wallabies, introduced by Rupert Baring in the 1950s, and augmented by a surplus from Dublin Zoo in the 1980s, numbering perhaps around 100 in 2017. The wallabies breed well, and some moderate culling is required to keep the population under control. Fallow deer were introduced, and by the mid-2000s formed a herd of about 200. There is also a herd of farmed cattle on the island, and a flock of sheep.
History Prehistory The island was of some significance in the Neolithic period in Ireland as a ground stone quarrying and production site for axes. Two outcrops of andesite, or Lambay porphyry as the specific rock variety is more commonly known, were utilised. The quarry site is unusual in Ireland for being the only Neolithic stone axe quarry with evidence for all stages of production, from quarrying to final polishing.
Classical period In the 1st century AD the Ancient Roman writer Pliny knew about the island and referred to it as Limnus or Limni. Its Irish name, Reachra, was eventually joined by a Norse name based on the root word ey for island. A number of Iron Age burials were discovered on the island in 1927, during works on the island's harbour. The finds included a number of Romano-British items, and the site has been interpreted as possible evidence for the arrival of a small group of refugees from Brigantia, fleeing the Romans from 71 to 74AD.
Ptolemy's Geography in the 2nd century AD may have been describing Lambay when it mentions Εδρου (Edrou). PIE *sed- 'to sit, settle' had descendants in many languages, including Greek ἑδρα (hedra) 'sitting place' whose many specific uses included 'base for ships'.
Early Medieval St. Columba is reputed to have established a monastic settlement on Lambay 530 AD, which passed to Colman and a line of successor abbots and at least one bishop. The religious settlement was raided by Vikings in 795, resulting in the church and buildings being ransacked and burned. Surveys in the early 20th century found remains of an enclosure to the south of the present chapel, and these, and modern satellite photography, suggested it was a moated site.
Late Medieval Sitric, a Danish King of Dublin, granted Lambay to Christ Church Cathedral, and in 1181 Prince John granted it to the Archbishops of Dublin. This was reconfirmed by King Edward in 1337 and by King Richard in 1394. A later archbishop gave the rents of the island to the nuns of the Augustine Grace Dieu Abbey and school near Swords, County Dublin for the upkeep of their establishment. He also gave the tithes of Lambay's rabbits to the nuns – at that time the rabbit taxes were worth 100 shillings a year.
In 1467, it was provided by statute that the Earl of Worcester, then Lord Deputy, be granted Lambay to build a fortress for England's protection against the Spaniards, French and Scots. Worcester paid the Archbishop of Dublin 40 shillings per annum and though he had a licence to build a castle on Lambay it is not certain that any fortification was actually built.
Early modern During the English Reformation in the mid 16th century, George Browne, the English Augustinian Archbishop of Dublin gave Lambay to John Challoner, the first Secretary of State for Ireland, for a rent of £6.13.4. The conditions were that Challoner would within six years build a village, castle and harbour for the benefit of fishermen and as a protection against smugglers. He was to inhabit Lambay "with a colony of honest men". He was a very active man who worked four mines for silver and copper and bred falcons on the island's many cliffs. During this period, Lambay Castle – a small blockhouse or fort – was built on the western side of the island.
Throughout most of the reign of Elizabeth I, Challoner owned Lambay but in 1611 the island was granted to Sir William Ussher and his heirs. James Ussher, later the Anglican Archbishop of Armagh, took up residence on Lambay in 1626. By 1650 he had moved to London; he was highly respected by Lord Protector Oliver Cromwell and was buried in Westminster Abbey. The island remained in the possession of the Ussher family, renting from the Church of Ireland See of Dublin, under Crown tenure, for 200 years.
During the Williamite war in Ireland, the island was used as an internment camp for Irish soldiers. More than one thousand of them were imprisoned there after the Battle of Aughrim in 1691; some died of wounds and starvation.
In the 17th century, exploratory mining was again undertaken on the island but it did not develop into an industrial activity.
Georgian and Victorian era
In 1805, the leasehold of Lambay was inherited by Sir William Wolseley, and in 1814 it was acquired by the aristocratic Talbot family of Malahide. In the period following the Talbot de Malahide acquisition both a Catholic chapel and a national (primary) school were built.