Inchkeith (from the Scottish Gaelic: Innis Cheith) is an island in the Firth of Forth, Scotland, administratively part of the Fife council area.

The late 9th century Sanas Cormaic, authored by Cormac mac Cuilennáin, suggests that the word had disappeared from the Gaelic of Ireland by that period, becoming coill; he states "coit coill isin chombric", that is, "coit is Welsh for wood", and explains that the Irish place-name Sailchoit is partly derived from Welsh.

[12] Although Scottish Gaelic was closer to Brythonic than Irish was, the Life of St Serf (written before 1180) calls the island Insula Keð, suggesting the possibility that the specific element in Inchkeith was not comprehensible to that hagiography's anonymous author or translator; if we could be sure that the author was Scottish, rather than an English or French incomer, this could be taken to mean that the word was probably not comprehensible even in Fife Gaelic in the 12th century.

In the days when people were compelled to cross the Firth of Forth by boat as opposed to bridge, the island was a great deal less isolated, and on the ferry routes between Leith/Lothian and Fife.

This was the period when the Scottish Wars of Independence were in full swing, and decisive battles were being fought in the Lothians and in the Stirling/Bannockburn region, and so the island was effectively in the route of any supply or raiding vessels.

The Grandgore Act was passed in September 1497, causing Inchkeith, as well as other islands in the Firth, such as Inchgarvie, to be made a place of "Compulsory Retirement" for people suffering from this disease.

Pitscottie's version of the story, written in Scots language and given here in modern spelling beneath, was;"And also the king gart tak ane dum woman and pat hir in Inchekeytht and gaif hir tua young bairnes in companie witht hir, and gart furnische them of all necessar thingis pertening to thair nourischment that is to say, meit, drink, fyre and candell, claithis, with all uther kynd of necessaris quhilk (is) requyrit to man or woman, desyrand the effect heirof to come to knaw quhat langage (or, "leid") thir bairnes wald speik quhene they cam to lauchfull aige.

His force of marines was ordered to reinforce the island, so they built a large square fort, with corner towers, on the site of the present day lighthouse.

[27] On 22 June Regent Arran's Privy Council ordered that all the towns and burghs on both sides of the Forth should contribute a workforce of 400 men to strengthen the fortifications, and pay their wages of two shillings for 16 days.

[28] After the end of the war of the Rough Wooing, the island was occupied by the French, under Mary of Guise, during her period as the Regent of Scotland between 1554 and 1560.

[33] During the siege of Leith, the English commander Grey of Wilton obtained a description of the fortress as it stood on 17 April 1560.

As the English admiral William Wynter was trying to blockade the island and cut off supplies, the garrison was eating oysters and periwinkles gathered at low water and fish caught with angling rods.

[36] She inspected the garrison, and a stone from the original gateway with "MR" (i.e. Maria Regina) and the date still exists, built into a wall below the lighthouse.

[37] The cannon were repaired in Edinburgh Castle by David Rowan, "master melter" of the artillery, who was paid for cleaning out the rusty touch holes in February 1566.

The Captain of the garrison, Robert Anstruther, was rewarded with all the ironwork timber and slates to be salvaged, and ownership of the island was given to John Lyon, 8th Lord Glamis.

James Grant lists subsequent owners of Inchkeith - in 1649, he says, the "eccentric and sarcastic" Sir John Scott of Scotstarvit, going on to be owned by the Buccleuch family, forming part of the property of the Barony of Royston, near Granton.

[citation needed] In the late 18th century, James Boswell's The Journal of a Tour to the Hebrides with Samuel Johnson (published in 1785) mentions Inchkeith, upon which Boswell and Dr. Johnson alighted, noting that the now-uninhabited island had a profusion of "luxuriant thistles and nettles", a "strongly built" fort, and "sixteen head of [grazing] black cattle".

By 1911 the shore was being covered in Barbed Wire and by the end of the First World War a series of pillboxes had been built on the beaches round the island.

During World War I, the Royal Navy battleship HMS Britannia, at the time a part of the 3rd Battle Squadron in the Grand Fleet, ran aground at Inchkeith on 26 January 1915, suffering considerable bottom damage.

[45][46] Inchkeith was the HQ of the Outer Defences of the Firth of Forth in both wars, in conjunction with batteries at Kinghorn, on the north shore, and Leith on the southern.

In the Second World War new batteries were established further east at Elie and Dirleton but Inchkeith remained fully armed.

In May 1940, the island was issued with 40 "Board of Trade, Rocket Flares, Red", for alerting in the event that an invasion was attempted (or spotted).

The garrison of the island was over 1100 at its peak in the Second World War, with dozens of buildings, emplacements, fire control centres, and Nissen huts, many of which remain in varying states of repair.

Operation Bodyguard was the overall Allied strategic deception plan in Europe for 1944, carried out as part of the build-up to the Invasion of Normandy.

The major objective of this plan was to lead the Germans to believe that the invasion of northwestern Europe would come later than was actually planned, and to threaten attacks at other locations than the true objective, including the Pas de Calais, the Balkans, southern France, Norway, and Soviet attacks in Bulgaria and northern Norway.

Operation Fortitude North's fictional British Fourth Army were based in Edinburgh, and spoof radio traffic and Double agents were used as means to disseminate the misinformation.

On 3 March 1944, members of a "Special RS (Royal Signals) Unit" from the British Fourth Army landed on Inchkeith, with a detachment of 22 men and 4 officers, with two radio vans.

At the beginning of April, a further 40 men arrived, and proceeded to stage mock attacks of the Inchkeith defences via the cliffs, until their departure in September.

A diaphone system providing 4 blasts of 1.5 seconds once every minute was installed on Inchcolm, operated by radio telephone from Inchkeith.

The Northern Lighthouse Board removed the permanent lightkeepers, and sold the island to businessman Tom Farmer (founder of Kwik-Fit).