Location: At the northern end of the chain of Treshnish Isles on two small islands 3 miles (5 km) SW of Treshnish Point on Mull and 12½ miles (20 km) N of Iona. Cairnburgh Castle’s defences are split between two small isles, Cairn na Burgh More and Cairn na Burgh Beg, which lie only a few yards apart. On the isle of Cairn na Burgh More the castle consists of a courtyard, barrack block, chapel and guard-house. On the nearby smaller isle of Cairn na Burgh Beg is a lesser defence, including another guard-house and a well. The Treshnish Isles guard the Passage of Tiree with the mountains of Mull to the east and the low islands of Tiree and Coll and the open Atlantic Ocean to the west. Exposed to the open ocean and having no settlements or good landing sites, they are most often viewed and admired at a distance.

Origin: Cairnburgh Castle dominated the north-south ocean sea route to Islay and Ireland as it passed by Mull and Ardnamachuran Point. It also and guard the entrance to the sea Loch Tuath inside passage along the west coast of Mull. Thus Cairnburgh Castle strategically controlled access to the heavily used Hebridean inside passage sea trade routes.

The builder is unknown but it was most likely originally a Viking fortress called Kiarnaborg.  The earliest reference to Cairnburgh Castle appears in the Norse Sagas in Haakon’s Saga – which was composed during the second half of the 13th C.  It first appears in records in 1249 as one of four Hebrides island castles that Ewan de Ergidia, newly appointed 3rd Chief of Clan MacDougall of Lorne held for King Haakon of Norway. In 1249, a few months after Ewan received the castle in his Hebrides island realm from King Hakon of Norway, Alexander I King of Scots arrived at Kerrera with a fleet to demand that Ewan surrender his Norwegian island castles to Scotland.  However, Ewan loyally carried out his sworn duty as their keeper for Norway and refused King Alexander’s demand. Ewan then had to flee into exile in Norwegian territories where he remained for five years until his restoration to his Argyll lands in 1255.  A decade later Cairnburgh Castle was part of the island territories purchased by Scotland from Norway in the 1266 Treaty of Perth.

After the MacDougall defeat by Robert I (Robert the Bruce), Cairnburgh Castle was forfeited to the Crown in 1309 which would then keep it as a royal castle of the King of Scots. Then the castle was occupied by his allies, the MacDonalds to be held in their custody as its Keepers on behalf of the crown for the next 184 years. In 1343 David I, King of Scots, confirmed John (MacDonald) of Islay as custodian of the Royal Castles of Cairn na Burg Mor and Dunchonnell. In September 1354, the MacDougall Chief, Johannes de Larin Dominus Ergadie “John of Lorne, Lord of Argyle” as he was styled in the document, made an indenture with the MacDonald Chief, John Lord of the Isles, to post facto recognize the MacDonald possession of those former MacDougall islands which had already been confirmed by charter in 1344 to John, Lord of the Isles, by David II King of Scots. This 1354 indenture effectively recognized Bruce’s seizure of these MacDougall properties in 1310 and his grant of them to the victorious MacDonalds.  The MacDougall Chief formally relinquished MacDougall claims to the Isles for Mull, the north part of Jura, Tiree, and the former MacDougall Treshnish Isles fortresses of Cairnburgh and Dunchonnell in favor of the MacDonalds. In turn the MacDougall Chief received the right to build certain ships and received MacDonald recognition of King David II’s restoration to the MacDougalls of some of their forfeited Lorn lands still held by the crown. Their 1354 agreement specified that no member of Clan Fingon, the MacKinnons, was to be given custody of Cairnburgh.

In 1495 following the 1493 forfeiture of the MacDonald Lordship of the Isles, King James IV confirmed MacLean of Duart as Keeper of Cairnburgh Castle. In 1504 with MacLean in rebellion the Kings’ forces besieged the castle and after it fell the castle was turned over to the Kings strong supporter Archibald Campbell, Earl of Argyll. In October 1604 the Campbell Earl of Argyll was granted a Commission of Fire and Sword to purse the MacLeans who at the time were listed as the Keepers of Duart and Cairnburgh.  It was captured by the Covenanter army General David Leslie in 1647 and subsequently taken by Oliver Cromwell’s army in the 1650s, when books and manuscripts from Iona which had been brought here after the Reformation for safe-keeping were destroyed.

In the spring of 1675 the MacLeans met at Aros Castle and agreed to garrison Cairnburgh Castle against the Campbell Earl of Argyll. It was attacked by the Campbells in 1679, but held out, although was surrendered once again by the MacLeans in 1692. Cairnburgh was garrisoned by Government troops during the Jacobite Rebellions of both 1715 and 1745 before being finally abandoned by the permanent government garrison, presumably sometime after the 1745 Jacobite uprising.

Description: Cairnburgh Castle guarded the ocean passage at the western edge of their realm of the Lords of Lorne.  This old castle was a vital link in the MacDougall’s ring of power and one end of the chain of transmitters of beacon fire warnings.  Such a fire signal could be relayed from the island of Cairn na Burgh More along the chain of castles which re-transmitted these beacon fire danger warnings. It is said that beacon warnings of approaching could be transmitted 100 miles (160 km) in two hours with the degree of danger conveyed by the number of fires lit at the beacon. 

The Treshnish Isles have been likened to a fleet of ‘Dreadnoughts in line astern’ or ‘tabular icebergs broken from a great ice sheet’. Cairn na Burgh island and its neighbors of the Treshnish archipelago are guarded by treacherous reefs. A rather spectacular natural arch has been carved by the waves pounding up against the island’s northern point. Cairn na Burgh More has a green grassy tabletop. Fortifications occupied the adjacent islands of Cairn na Burgh More and Cairn na Burgh Beg a few yards apart.  The cliffs of red-brown columns of volcanic basalt are inhabited by nesting sea birds, while seals often rest on the rocks below. In the teeth of an Atlantic gale, Cairn na Burgh must be a wildly buffeted place.

Cairn na Burgh Beg (Cairnburgh Beg) is the smaller rocky island which represents the most north easterly of all the Treshnish Isles. Cairn na Burgh Beg has an area of 3 acres (1.2 ha) and rises to 72 ft. (22 m) immediately to the west is the slightly larger Cairn na Burgh More. These grassy islands are both remnants of ancient lava flows, and have distinctive flat tops trimmed with cliffs. There are the remains of a castle here but landing is difficult due to strong tidal races. It was probably fortified to secure the approach to the principal stronghold on the adjacent island. All the surviving buildings on Cairnburgh Beg, including the curtain-walls, appear to be of 16th or 17th C. date.

Cairn na Burgh More (Cairnburgh More) is the larger rocky island of 3.4 acres (1.36 ha) and rises to a height of 114 ft. (35 m).  It was garrisoned until the middle of the 18th century. Ruins of the old stronghold stand exposed upon this high treeless pedestal. Although the chapel may date from the 15th C., the other surviving structures are from the 16th or 17th C. 

The castle was subject to an archaeological investigation by the University of Glasgow in 2006, on behalf of its owners, the Hebridean Trust which acquired the Treshnish Isles in 2000. Historic Environment Scotland describes the isle of Cairn na Burgh More as follows:

Cairn na Burgh More is divided into two portions of unequal size by a deep gully running approximately from W to E. The castle stands on the larger (S) portion (see plan), which comprises a gently sloping summit some 1.36 ha (3.4 acres) in extent situated up to 34m above sea-level. On the NW, W and SW sides, sheer cliffs make ascent impossible, and the remaining sides, where the cliffs are lower and less steep, have been enclosed by a curtain-wall, of random rubble masonry laid in lime- mortar. This varies the thickness from 0.60m to 1.40m and is best preserved on the E side, where it rises to a maximum internal height of about 2.5m. It follows a sinuous course, following the cliff-top. Natural clefts in the rock have been sealed off by carrying the wall down to the base of the cliff. Two short stretches are of dry-stone masonry.

The best-preserved buildings are the chapel and the barrack, both of which stand partially to wall-head level. The former measures 7.9m from E to W by 4.9m transversely within walls some 0.7m in thickness; on its S side there is a small enclosure surrounded by a dry-stone wall. The barrack, two storeys high, measures 16.2m from SW to NE by 6.3m transversely over walls 0.7m in thickness.

A little NE of the barrack are the remains of a small oblong building identified on a mid-18th C. Board of Ordnance plan as a guard-house. This measures 7.9m by 6.4m over dry-stone walls some 1.5m in thickness. There appears to have been a doorway on the S side, facing towards a small adjacent building of sub-oval plan not indicated on the Board of Ordnance drawing. To the SE of the barrack are the remains of two other dry-stone buildings, the smaller of which is identified on the Board of Ordnance plan as a ‘house for fireing’ or fuel-store. The only other structures on the island are a group of three or four dry-stone buildings of sub-rectangular plan lying immediately above the foreshore and close to the principal entrance, but these may be of comparatively recent origin. About 75m SW of the barrack, a shallow drainage-trough of natural origin runs across the summit from NW to SE. The central portion of the trough has evidently been converted into a catchment pool by the construction of an earthen dam across its lower end, and the Board of Ordnance plan shows that this pool served the garrison as a well in the 18th C.

NM 305 448 A standing building survey of the barracks, chapel and curtain wall on Cairn na Burgh More, Treshnish Islands, was carried out on behalf of the Hebridean Trust in August 2006. This project was undertaken in order to assist with the conservation and restoration of the structures and to assess the archaeological potential for further archaeological works.

 

References:

1 – Technical information has been provided by the Canmore Database site of Historic Environment Scotland and their Cairn Na Burgh sites may be visited at:

2 – See also the Gazetteer for Scotland site Cairn Na Burgh at: 

3 – Journeying in MacDougall Country by Walter M. Macdougall, Past President of the Clan MacDougall Society of North America on pages 38, 217 contains descriptions and notes on this site. This excellent book is available from Lulu.com with profits going to the Dunollie Preservation Fund from its book sales at http://www.lulu.com/shop/walter-macdougall/journeying-in-macdougall-country/paperback/product-2242050.html