My understanding is that the Anglo-Norman army took up the longbow after 12th century battles with the Welsh. Were the Welsh using the longbow to such a devastating effect that they caused this massive change? Where did they get the longbow and the archery culture from to cause this uptake
Archers are described as part of William the Bastard's army during Hastings; were they using large selfbows made from continental yew or something different?
Imperial Rome had Sagittarie as well as archer auxilliae during their occupation of Britain but they (to my understanding) exclusively used Eastern composite bows. Did the natives pick up archery in battle from them or did they already have such (any information I hear from the Roman conquest of the island only mentions the chariots and light infantry scrum).
Is there any information about early middle ages battles involving the bow? Did the anglo-saxons and Scandinavians truly use exclusively spear and shieldwall combat? Was there any ranged weapon designed to break a shieldwall or skirmish?
Is there any information about the make up of a Welsh army pre Norman invasion and if that involved an archer corps?
The longbow has a long history in Britain, and the longbow has a long (but less long) history as an English military weapon. While there is a school of thought that believes that the Welsh/English longbow was a new weapon, replacing an older "short bow" that had been used beforehand, it appears instead that the longbow existed continuously, at least from the early Medieval period through to today. The oldest longbows found in Britain are thousands of years old, dating to the mid-3rd millennium BC, e.g., the Meare Heath, Ashcott Heath, and Rotten Bottom bows (although if we insist that a "longbow" must have a D-shaped cross-section, we would label the Meare Heath bow as a flatbow rather than a longbow, despite its longbow length (and a strict insistence on D-sections would exclude some of the Mary Rose bows, so it's best not to be so strict)). There is also other archery equipment from the time, such as the items found in the grave of the Amesbury Archer.
What we don't have good evidence for is how common archery was at time of the Roman invasions and conquest. Caesar's Gallic Wars describes the Gauls using the bow and arrow, and we have a similar lack of evidence for Continental archery of the time, so clearly archery could have been in use, despite the lack of finds. Sling stones and clay bullets are found in large numbers at some sites, and clearly the sling was an important military weapon. However, stones and clay bullets are much more likely to survive to be found than bows and arrows, especially arrows with organic heads. Perhaps the bow was also an important military weapon, but heads were usually made of bone or hardwood.
Regardless of the pre-Roman question, the longbow was present in the post-Roman pre-Norman period. Multiple bows and pieces of bows have been found (far, far more of them than post-Norman Medieval bows). In addition to the archaeological evidence, literary source support the Anglo-Saxon and Scandinavian use of archery. For example, in The Battle of Maldon, we have
The watery streams separated them. It seemed to them too long
before they could muster their spears together.
There they stood in press alongside Pante’s stream,
the greatest of the East-Saxons and the spear-hordes.
Nor could any of them afflict the other side,
except those who were felled by the showering of arrows.
and
He did not flinch back at all at the war-play,
but he sent forth arrows very frequently;
sometimes he shot into a shield, sometimes he skewered a warrior,
more than once in awhile he gave someone a wound,
so long as he was allowed to wield weapons.
Archery appears in various Viking sagas, notably in naval battles. Archery was still seeing use in Anglo-Saxon hands at the very end of the pre-Norman period, with Harald Hardrada being killed by an arrow at Stamford Bridge (at least according to some accounts of the battle, which added to the arrow in the eye at Hastings makes archery a significant killer of kings named Har(a|o)ld in 1066).
The longbow was also in use under Norman rule before the Welsh wars which supposedly introduced the longbow to the English. In the Assize of Arms of 1252, some income groups are required to own bows:
ad xl a solidatas terre et eo amplius usque ad centum solidatas, gladium, arcum, sagittas et cultellum.
"for those with 40 shillings of land and more, up to 100 shillings, a sword, a bow, arrows, and a knife."
ad catalla x. marcarum, gladium cultellum, arcum et sagittas
"those with 10 marks of goods a sword, knife, bow and arrows"
Omnes eciam alii qui possunt habere arcum et sagittas extra forestam babeant ; qui vero in foresta arcus et pilettos.
"All other people [i.e., those below the various wealth brackets listed] shall have a bow and arrows when out of the forest, and in the forest bows and piles [blunt arrows(?)]."
Strickland and Hardy (2005) discuss the case against the shortbow (they don't believe in it) in more detail.
One can then ask what happened due to the Welsh wars. Edward I had substantial numbers of archers in his armies in his Welsh wars - about 25% archers. Over half of his army was Welsh, and it's likely that many of his archers were Welsh. A few decades later, about 20% of his army was archers, about half English and half Welsh. However, these numbers of archers are far lower than seen in later English armies. Perhaps very little relevant to changes in longbows and their use in war happened at the time.
The big shift to more archers comes under Edward III (whose army at Crecy was half archers). Perhaps the most important driver was the professionalisation of the army, with soldiers being paid professionals rather than providing feudal service.
To quote myself from a past answer to a similar question in https://www.reddit.com/r/AskHistorians/comments/9uccx0/what_was_the_origin_of_the_longbow/ there might have been a change to higher draw weight bows due to the Welsh wars, but the evidence is scanty:
It has been suggested that what the English adopted from the Welsh was the use of higher draw weight bows. This is based on the comments about the power of Welsh bows by Gerald of Wales. According to this version, the English were already using longbows, but of lower draw weight than their later bows. Being suitably impressed by the effectiveness of Welsh archery, they switched to using more powerful bows themselves. The evidence supporting this story is slim - just Gerald of Wales. A shift to higher draw weights might well result from more widespread use of armour, but the requirement that bows be powerful to be able to penetrate armour is fairly obvious (and was known to many peoples around the world), and the English were quite capable of figuring it out themselves. Also, this would not be a change from weak bows to powerful bows, but a change from powerful bows to even more powerful bows.
References:
The Rottom Bottom bow: https://canmore.org.uk/site/71910/rotten-bottom
The Amesbury Archer: https://salisburymuseum.org.uk/collections/stonehenge-prehistory/amesbury-archer
The Battle of Maldon: https://anglosaxonpoetry.camden.rutgers.edu/battle-of-maldon/
Assize of Arms of 1252: pp 482-483 in Close rolls of the reign of Henry III, https://archive.org/details/closerollsofreig04grea/page/482
Matthew Strickland and Robert Hardy, The Great Warbow, Sutton, 2005.
/u/wotan_weevil has written an excellent answer, so I thought I might touch briefly on this part of your question:
Did the anglo-saxons and Scandinavians truly use exclusively spear and shieldwall combat? Was there any ranged weapon designed to break a shieldwall or skirmish?
As previously mentioned, there's definite evidence of Anglo-Saxon and Scandinavian use of bows, but javelins also played a very important role in Anglo-Saxon warfare. The Battle of Maldon also provides evidence of their use:
Then loosed they from their hands the file-hard lance,
The sharp-ground spears to fly.
Bows were busied - buckler met point
Bitter was the battle-rush, warriors fell
Similarly, at the Battle of Brunanburh, the Anglo-Saxon Chronicle notes there was "many a northern warrior shot over his shield." Javelins were particularly useful because of their potential to disrupt a shield wall and leave it vulnerable to breaking. An arrow in a shield may be disregarded, but several feet of ash hanging out of your shield is going to render it quite useless.
To add to the excellent answers of /u/BRIStoneman and /u/wotan_weevil, the history of the Anglo-Saxon shortbow goes back into at least the 19th century. It's not something I've looked into much past Charles Oman, but the idea that earlier medieval bows were not much longer than 150cm goes back at least to Viollet-le-Duc, who used the Bayeux Tapestry and the tympanum from Vézelay Abbey (carved in the early 12th century) as the basis for his estimate of length. Viollet-le-Duc didn't suggest, as J.E. Morris did, that the English had borrowed the longbow from the Welsh, but he did suggest that there was a gradual lengthening of bows from no more than 150cm before the 12th century, to around 170cm in the 13th century and then, first in England, to around 190cm in the 15th century (and possibly the 14th as well - I admit to using Google Translate here). Interestingly, this is pretty much identical to the idea proposed by Jim Bradbury in The Medieval Archery, namely that the longbow always existed, but was commonly around 5 feet early on, and then lengthened as time went on. He doesn't cite le-Duc, so it might be simply a case of similar conclusions drawn from the same body of evidence.
In any case, the popularization of the argument that the Anglo-Saxon and Norman bows of the 11th century were weak shortbows started in English language literature with Charles Oman, whose 1885 essay, The Art of War in the Middle Ages, argued that, since the Bayeux Tapestry only showed the archers drawing to their chest and that Richard I preferred crossbows to bows, the bows in use prior to the Welsh campaigns of Edward I must have been short and weak. Since Oman saw the English kings' preference for crossbows ending at the end of the 13th century in favour of longbows, he decided that the shortbow, in use since Saxon times, must have finally been replaced by the "Welsh" longbow under Edward I. This argument was taken up and expanded on by J.E. Morris in The Welsh Wars of Edward I, which essentially cemented the concept as dogma.
The position that the Welsh longbow was adopted by Edward I was so entrenched that even Robert Hardy, who denied the existence of the shortbow in his Longbow: A Social and Military History, believed that Edward I had adopted the more powerful Welsh longbows in the place of the weaker English longbow and set about training the English peasantry in them. It wasn't until Jim Bradbury's The Medieval Archer that this dominant narrative was challenged, as he pointed out that Edward I's use of archery was no different from any previous English king and that Welsh archers actually played very minor roles in his victories, if at all. This narrative was then taken up and expanded on by Matthew Strickland in The Great Warbow, and the idea of the English adopting the longbow from the Welsh was crushed once and for all. It now seems that the longbow was not used in great numbers until the early 14th century, where it seems to have been first used in the new fashion (in combination with dismounted men-at-arms) at the Battle of Boroughbridge.
Of course, none of that really answers the question about the degree to which the Anglo-Saxons used archery. I'm actually only aware of a single archaeological finding of an Anglo-Saxon bow is from a grave in Kent, excavated in the mid-19th century, which contained 24 arrowheads (both barbed and bodkin) and a line of darker decomposed wood, outlined against the chalk, about five feet in length. Perhaps /u/wotan_weevil can provide some more examples of bows and bow fragments from Anglo-Saxon England, as he seems to be more up to date on the archaeology. In addition to this one find, there is a small number of graves containing arrowheads, as well as scattered examples found in villages, manors and towns.
From these finds, and the limited descriptions of their use in Anglo-Saxon poetry, it is apparent that the Anglo-Saxons did use archery to some extent. The degree to which it was in use, however, is debated. The dominant view holds that it was in use, but was relatively rare in comparison to the use of javelins. This fits the archaeological evidence and the relative lack of reference to it in Anglo-Saxon literature, as well as explains why William the Conqueror's archers were so effective, but it may not be the whole story.
Unlike in the Merovingian, Carolingian and Scandinavian worlds, England from the 8th to 10th centuries does not appear to have had an archery culture among the elite members of society. Whereas we can see bows being among the necessary weapons for the professional warrior in Western and Northern Europe at this time, England does not seem to have followed this trend. The lack of reference to archery may therefore be because they were considered low status weapons, and so they only appear in very few pieces of literature and were not generally considered a weapon of high enough status for a man to be buried with.
This is all, of course, speculation, and the question is not likely to be solved by anyone in the near future.
As a final point, while Robert Hardy and Matthew Strickland have argued that the shortbow never existed, three shortbows from Anglo-Norman military sites in Ireland have been found, with one complete bow measuring just under 130cm, and the two fragments being long enough to determine that their approximate lengths would have been 140cm and 150cm when complete. As an arrow with a bodkin head, only long enough for a 24" draw length, was found near the complete bow in Waterford, these were likely to be military, not civilian bows. Similarly, a recent replica of the Wassenaar Bow, which was ~160cm in length (and probably only 150-155cm between the nocks, based on the measurements) drew to no more than 26". The Aalsum bow, which dates to the same period, is similarly short, if less powerful.
This very strongly suggests that longbows - two longbows from 10th century Scandinavian sites measure around 190cm in length - co-existed with shorter bows, whose draw length varied between 24" and perhaps 28", in comparison to the 30" draw of the longer bows. These shorter bows, to judge by their dimensions and the replicas that have been made, did not necessarily have lower draw weights, although their shorter length did make them less efficient. Why they were used in conjunction with longer bows with a more efficient draw length - and often a higher draw weight (I've estimated the Hedeby bow at 140lbs @ 30" at the minimum) - is not a question I've been able to answer yet.
TL:DR
The English did not adopt the longbow from the Welsh, and had probably been using them for some time before the early 14th century, when the longbow first began to be used as a major part of the tactical scheme. While the Anglo-Saxons definitely did have archers, their extent is unknown. It is possible that archery became more popular under the Anglo-Norman kings, who knew and respected the weapon, or it could merely have received more focus because they had less disdain for it that previous Anglo-Saxon rulers. Finally, the shortbow did exist, but it co-existed with the longbow and was not a weak weapon, but a powerful military bow.
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