I've recently been reading through the 1547 Inventory of Crown Possessions, as you do. This was compiled after Henry VIII's death and lists everything from the jewels, plate, tapestries and royal "close stools" in the palaces ... down to all the stocks of bows and arrows, buckets and spades, horseshoes and nails, in the many fortresses around the kingdom. In the armouries and garrisons of several fortresses there are references to what is called "wildfire", or sometimes "firework" which I take to be much the same thing.
 
For example at Calais, in the Wildfire House which was a specific section of the larger Ordnance House, there were:
"... 30 empty trunks; 30 Wild fire trunks; 100 wild fire hoops; 10 great wild fire casting pots of both sorts; 6 small wild fire casting pots; 7 balls with short staves; 2550 empty wild fire pots of both sorts; 40 wild fire pikes."
... while at Boulogne there were:
"... 4 great balls of wildfire; 50 small balls of firework; 3 pikes for firework; 6 trunks of firework ..."
 
And it seems wildfire wasn't limited to land use. A separate, earlier listing of the muntions on board the Mary Rose in 1514 included:
"... 74 arrows of wildfire, 2 balls of wildfire, 8 heads for arrows of wildfire, 29 hooks for arrows of wildfire..."
 
Wildfire or firework would therefore seem to be some sort of incendary material, presumably a bit like Byzantine Greek Fire or modern napalm - that was either thown in pots or as as balls, fired attached to arrows, or thrust forward attached to pikes. I've never come across it before and the only, rather meagre, information I've managed to find was this illustration in 'Tudor Sea Power: The Foundation of Greatness', by David Childs (2009) p.81, but unfortunately he gives no more information.



So what exactly was "wildfire": how was it made, what was its composition, and how was it used ... indeed was it ever much used, and to what effect?

According to this blogger "wildfire" saw use during the Wars of the Roses and was "fired" from the battlements of the Tower of London against a York militia that had been allowed through the city's defences. His image reproduced below suggests a rudimentary flame-thrower, and he mentions it being based on a "napalm" type substance.



I've a few problems with this, not least the efficacy of such a weapon in those exact circumstances. However I'm sure I've also read that "wildfire" referred to combustible material attached to projectiles, such as crossbow bolts and catapult ordnance, and that it was used especially in sieges of strongholds (the exact opposite in other words of the blogger's claim) where the intention was to ignite any non-stone material and even generate strategically chosen fires of very high temperature that could weaken stone ramparts and curtain walls through cracking them from within.

The image you posted seems to support this, apart from the fact that arrow projectiles with these attached payloads may not have been feathered (not much point) and instead relied on being fired at relatively close quarters and with great force.

There's a description of various forms of incendiary devices - trumps, hoops etc - in Ernle Bradford's "The Great Siege : Malta 1565".

Cursory references here too - http://historynuggets.blogspot.co.uk/2012/05/malta-1565.html

Sorry to bring the tone of scholarship of the board down but there is mention of 'wildfire' in George RR Martin's fantasy novels (source material for Game of Thrones TV show) A Song of Ice and Fire which substance was based on real world Greek Fire. I seem to remember there being a character nicknamed "Madge Wildfire in HMF Prescott's book about the Pilgrimage of Grace The Man on a Donkey but I could only find (via Google) a character with that nickname in Walter Scott's Heart of Midlothian.  Mr Scott was never my favourite author but I didn't hate him either but I thought he always used 6 words when one would have sufficed.  Google also said that there had been a steam engine called "Madge Wildfire".

I noticed yesterday when I went searching to see if I could find further reference to "wildfire" (as a Tudor might have meant it) that I was inundated with hundreds of "results" pointing to "Game Of Thrones" and the author's fantasy-bombs. One problem with Google as a research tool - you have to wade through Thrones, Kardashians, UFO abductees and penis enlargement aids etc to find anything of value these days. Unless of course you are a potential royal celebrity with a hankering after interstellar jaunts and a bigger willy.

I did however find a few references in a book at home about Late Middle Ages warfare (not specifically Britain but throughout Europe) and it appears the term covered a multitude of techniques and military hardware, so I'm still none the wiser as to what exactly was found in Henry VIII's posthumous inventory.

nordmann, are you saying you AREN'T interested in the Kardashians and UFO abductees etc?

Don't answer that, it's just me being flippant.

If the Kardashians were actually abducted by UFOs I am not sure the world would be all that poorer a place for it - I know mine wouldn't.

nordmann wrote:

If the Kardashians were actually abducted by UFOs I am not sure the world would be all that poorer a place for it - I know mine wouldn't.

Aren't aliens protected by various treaties? If so, you are at risk of indictment for threatening to inflict "cruel and unusual punishment" in the form of any or all Kardashians upon them - anal probes notwithstanding (who could withstand, let alone stand with, an anal probe, I wonder?).

In Charles Cruikshank’s excellent book ‘Henry VIII and the invasion of France’ (1990) – all about Henry’s French campaign in 1513 – he make’s a remark in the chapter concerning logistics:
 
“Siege warfare also called for a third type of gun – a weapon to be used not against walls, but against the people and buildings inside them: one that could, for example, lob a fused bomb, which would have a serious effect on morale, in addition to causing physical damage. These pot-guns, or mortars, were used with great effect at Tournai, and helped bring the townspeople to the point where they were thankful to throw their hand in.” My emphasis. (NB the city of Tournai had rather poor defences and in particular had only a few, rather antiquated cannon, and so the English could get in close to the walls and use of these short-range mortars, unlike at Therouanne where they had to keep their distance from the defenders' own artillery).
 
Unfortunately Cruikshank has little more to say about the details of this bombardment, but it is usually taken that such mortar bombs were cast-iron hollow shells, filled with gunpowder, and with a rudimentary fuse … and the use of such missiles is certainly well recorded in the early 17th century. Furthermore the wall paintings at Cowdray House depicting Henry’s siege of Boulogne in 1544, and completed within just a couple of years of the action, also seem to show this (the originals were destroyed in the 18th century but are known from 16th century copies).

Detail from one of the Cowdray House wall paintings of the 1544 siege of Boulogne - the mortars are at right, with behind them the gunners who appear to be hammering fuses into the mortar bombs supported on tall, three-legged stools:



But I'm not so sure.

In 1544 (and even more so at the siege of Tournai in 1513) producing liquid cast-iron was very new technology, and casting a hollow sphere, as opposed to a a solid ball, is no easy task at all. The first iron blast furnace in England was only built in about 1491 at Buxted in the Weald. One of the first uses for the liquid iron it produced was indeed solid cannon balls but it wasn’t until the 1540s that the first cast-iron cannon could be produced.

In 1541 William Levett was the royal "gunstone maker" (that is, he made cast iron cannon-balls) at a foundry in the Weald built by his elder brother in 1534. (Levett is not a normal English name, and the brothers may have originally come from an immigrant family - incidentally William Levett was also the village parson). In 1543 Levett brought in another foreign expert, Peter Baude, who had been casting bronze cannon for the King in London, and they built a new blast-furnace at Buxted specifically to try to cast iron cannon. They were successful, and the Buxted works produced the first one-piece, cast-iron cannon in 1543. Their early cannon went into fixed positions in coastal forts, where their great weight compared to bronze cannon did not matter much. Progress was rapid. A foundry with two furnaces was built in 1546, so that enough molten iron could be supplied at one time to pour into larger moulds and produce larger cannon. By 1549, 53 forges and blast furnaces were operating in the Weald, not all for military uses of course, but a dramatic increase nonetheless. The industry then more than doubled in the number of furnaces in operation over the following 25 years.
 
So in the 1540s casting iron cannon from one-off moulds was very much at the very cutting edge of technology, and I’m not at all convinced that the production of lots of hollow, cast-iron, mortar bombs was yet possible, nor even of any great commercial interest.
 
At the 1544 siege of Boulogne, where the gunners are supposedly depicted preparing cast-iron mortar bombs, were they in fact hammering the fuses into terracotta explosive pots? Or were these bombs actually non-explosive, incendiary pots of wildfire? Interestingly in the 1547 Inventory, while there are long lists of solid shot for all the various calibres of guns and cannon, made in both stone and cast-iron, I can find no listings for any mortar bombs at all … unless the mortars were expected to fire the wildfire pots already mentioned.

That 16th century mortars were used to lob incendary pots or balls of "wildfire" would certainly be borne out by this picture (unfortunately I didn't record the reference but I seem to remember it was from a book on ballistics and fortifications, printed in the Low Countries):

That's just a natural development from this :- https://www.youtube.com/watch?v=rAdC2K8-E4U

To a degree but as the video says, if you fire the projectile too soon after igniting it, it is likely to go out en route ... to late and you risk the trebuchet catching fire, or if using a cannon, an uncontrolled firing which would probably just scatter burning debris all over yourself. With a proper time-fused bomb you have time to light it and then fire, or just fire and rely on the windage flame to light the fuse. Similarly I suspect that if using wildfire, it would catch light very rapidly from the blast flame and burn hot enough not go out in flight. Again we come back to wildfire being a rather special incendary mixture, probably containing not just a ready fuel such as pitch, oil or tallow, but also an oxidant such as ammonium nitrate, as well as having sufficient wadding to give it a sufficiently 'solid' mass to hold together as a lump and be able to withstand the high rate of acceleration when explosively fired from the barrel of a gun.

I've finally managed to dig out my copy of Henry VIII: Arms and the Man, a lavish (and very heavy!) book published to accompany the Royal Armouries/Historical Royal Palaces exhibition of the same name from a few years back. It includes an incendiary dart (probably hand-thrown) from the Mary Rose, one a number of incendiary weapons found on the wreck, including 'lime pots' and 'mortar bombs'; unfortunately it doesn't go into more details on these. All were used for deploying wildfire.

The catalogue gives a 'recipe' from Biringuccio's Pirotechnica of 1540: ammonia, animal fat, arsenic, egg, juniper oil, linseed oil, mercury, naphtha, petroleum, pitch, quicklime. saltpetre, sulphuric acid, sulpher turpentine, undistilled wine, vinegar, wax and gunpowder.

The mixture could be placed in a linen bag and fixed to the end of a dart (the Mary Rose example is two metres long, with a silver fir haft and oak fletchings). Wooden fuse pegs were placed on the sides reaching into the mixture, and the whole area covered with pitch. This was then lit and thrown, so the whole thing ignited and spread on impact.

Naphtha, incidentally, was used in the 'Greek Fire' style flamethrowers employed by the Saracens during the Crusades.

Naptha, sulphur and pitch seem to have been major components in the pyrotechnic armoury of the Knights of St John during the siege of Malta.

Anglo-Norman wrote:

The catalogue gives a 'recipe' from Biringuccio's Pirotechnica of 1540: ammonia, animal fat, arsenic, egg, juniper oil, linseed oil, mercury, naphtha, petroleum, pitch, quicklime. saltpetre, sulphuric acid, sulpher turpentine, undistilled wine, vinegar, wax and gunpowder.

That's quite a mix of ingredients ... I'm not sure what the arsenic and mercury were for (and the mercury wouldn't be cheap either), nor the function of the wine and vinegar, especially as there's already sulphuric acid in it. But the rest would certainly give a highly infammable, sticky, napalm-like substance. I wonder if it was as much intended as a 'gas grenade', producing a choking, noxious, acrid smoke, as an incendary.

Of course starting with the ammonia (I assume that's actually ammonium hydroxide or ammonium nitrate) and sulphuric acid, one could distill this mixture to get nitric acid, and then if you dissolve the mercury in the nitric acid and add ethanol (distilled from the wine), and finally very carefully dry this to crystallize the solution, one could make mercury fulminate, Hg(CNO)₂. This is explosively unstable, ignition being triggered by heat, shock or friction, and hence it was commonly used during the 19th century in percussion caps for blasting explosives and in rifle ammunition ... but it was first prepared only in 1800 by the chemist Edward Charles Howard.

Thank's also for the comments about the Mary Rose, which seem to confirm my suspicion that Henry VIII's artillery, whether on ships or during siege operations, used incendary materials rather than true explosive bombs.

Meles meles wrote:

I wonder if it was as much intended as a 'gas grenade', producing a choking, noxious, acrid smoke, as an incendary.

I don't know about Henry VIII's reign, but certainly around the time of the Civil Wars, gunners were indeed using mortars to launch 'gas' bombs (not the term they used - I forget the 17th century name) containing noxious substances which were ignited to produce toxic fumes. How effective they were in practice is debateable, but at the least the results can't have been pleasant.