The Battle of Worcester was the decisive battle that concluded the third civil war in England (1650 to 1651). The battle was fought between the parliamentarian forces, led by Cromwell against the defending royalist forces, led by Charles II with the aid of a Scottish contingent led by the Scottish general, Lord Leslie. The majority of the battles during the third civil war were fought in Scotland and were themselves triggered by the parliamentarian invasion of Scotland to try to prevent the growing royalist support witnessed in the north. Three battles were fought north of the border between the parliamentarian and royalist supported Scots, at Dunbar and Inverkeithing; all three engagements were won by the parliamentarian forces. In retaliation for these defeats, Charles II led a counter-invasion of England, evading Cromwell’s Firth of Forth based forces. Charles forced a march to the south-west where there was strong royalist support, leading to Charles’ investment in Worcester to provide a rest for his men after a week of marches, and the setting for the subsequent battle.
The New Model Army
During the first 2 years of the first act of the English civil war, the parliamentarian forces had experienced varying degrees of military success against the royalist armies, mainly due to the reluctance of local militia to leave their homes for such a prolonged period, combined with the poor training of the majority of militias and associated forces. To resolve these issues faced by the parliamentarians, the House of Commons attempted to create one, united parliamentarian military force , the force would have the ability to deploy anywhere in England, Ireland and Scotland, an improvement from the previously immobile nature of the separate militias that were each tied to a single area or region within the country. Furthermore members of the new model army were trained and equipped to become full time soldiers instead of the ill-equipped and poorly trained militias. With a newly professionalised soldiery, the leadership also needed to be reformed and this lead to the abolition of parliamentary members becoming the military leaders. This proposal was disliked by the House of Lords, especially the Earl of Essex and his supporters. However the House of Commons forced the Lords to accept their proposal to create a single army by removing funds for the 3 armies and focusing said funds upon one new army. 
The new model army was created in 1645, composed of 6,600 cavalry and 14,400 infantry, a total of 21,000 men at arms. Within the cavalry were 1000 dragoons (mounted infantry, the Humvees of the 17th century). The infantry consisted mainly of musket, halberd and pike men. The monthly funding of the army was £60,000, increased to £120,000 by 1649, or the equivalent to £6,211,032 increased to £12,422,064. The new model army was financed by the great economic powerhouse of London, and received the best and most modern weaponry from the vast London workhouses.  The new model army now possessed an overwhelming advantage over the royalist forces. Improved discipline, weaponry and leadership allowed the new model army to become an extremely effective fighting force and vastly superior to the royalists.
This superiority was crucial during the third civil war of 1650 to 1651. The new model army was able to defeat the highly experienced Scottish army 3 times on their own soil and chosen battle grounds in Dunbar and Inverkeithing, damaging the Scottish morale and reducing their number. Poor morale, low numbers and exhaustion from the long march from Scotland to Worcester severely reduced the Scots’ appetite for defence at Worcester. 
Use of artillery
One book I found in the Library and Archives of Worcester Cathedral was written by a certain Captain Gerat Barry in 1634; titled ‘A Discourse of Military Discipline’. Barry was an experienced Irish mercenary and general of the 30 years’ war. His book is a guide to military discipline and organisation of 17th century Europe and includes an article on the successful use of artillery during combat. Barry states that an army should carry:
“15 haulfe cannones from 25. pounde bullet to 30.
16 culverines from 16. to 20. pounde bullet
- Demy Culverines.
- Falcones and falconettes” 
A total of 82 cannons for a large army, with shots of up to 66 pounds (30kgs) in weight.
Barry describes at great length the other necessities required by the artillery crew during battle:
“A greate quantitie of bulletes for youre greate ordenence, and a goode store of match, and bulletes for the smale (small) shott, a store of mattokes shoules and pickaxes, hatchettes and axes to cut woode and fagotes” 
Barry discusses the requirements to transport the masses of ordinance used in 17th century battles:
“To drawe a cannon of greate cice (size) in faire weather is required 18. or 20 horses, sometimes more if the situation be not goode, but in foole weather is required 24. horses […] for a demy cannon 12. or 16. horses (are required) ” 
Demy cannons of the 17th century could weigh up to 5600 pounds (2540kgs)  carried over often unpaved roads and rough terrain so warranted the use of such high numbers of horses and sometimes oxen. Carrying the cannons to battles was not the only logistical issue faced by the armies of 17th century Europe, the ammunition and gun powder also needed transporting to the battlefields. Wagons were used to carry these items:
“A stronge and goode wagon will carie 70. cannon shott […] required 4. or 6. Horses” 
Ammunition of cannons had some considerable mass, as before stated, up to 30 kgs per shot. Gunpowder required to shoot these bullets was another huge weight that needed transportation. Barry states that two thirds of the mass of the bullet was required in gunpowder for sufficient propulsion. A wagon carrying 70 shots of 66 pound (30kg) bullets required 3,469 pounds (1575kgs) of gunpowder.
The royalist and Scottish forces at Worcester severely lacked the necessary components for the effective use of artillery against the parliamentarian attackers. Due to the defeats at Dunbar and Inverkeithing, the Scottish artillery and artillerymen suffered huge losses, resulting in just 16 cannons arriving at Worcester and a small group of surviving artillerymen . The logistical issues of transporting such huge masses of ammunition and gunpowder from Scotland meant that the Scots were running low on ammunition before the battle had even started. Worcester’s Fort Royal cannons were still in place from the previous siege in 1645, so the Scots utilised these pieces of ordinance. However, there was very little gunpowder and ammunition left in the Fort Royal stores, the magazine in Worcester contained 7 small firkins (around 55lbs or 25kgs) of gunpowder, which had been carried away by the local militia upon the news of Charles’ advance.  The use of these commodities was in no way restricted, as one parliamentarian soldier described: they fired ‘as if they did not lack powder and ammunition’ . These factors meant that the defending royalist and Scottish armies were unable to use artillery sufficiently and for the entire course of the battle, yet another reason for failure, as artillery had become an integral part of 17th century warfare, against the parliamentarian attackers. 
Events of the battle
The Scottish and royalist force had been resting in Worcester for several days before Cromwell and his parliamentary force arrived at Worcester from Evesham on the 2nd of September. The Scots and royalists numbered around 12,000 whilst Cromwell had 28,000 men at his disposal. Cromwell approached Worcester from the south, using Red Hill to the south-west of Worcester to place his artillery to bombard the city and defenders. From the southern approach to Worcester, there were only 2 places to cross the river Teme and Severn that straddled the city, Powick Bridge that crossed the Teme to the south west, and a small fording path east of Powick Bridge. To guard these two bridges, commanders Keith and Pitscotte were deployed with a regiment each, Keith on Powick Bridge and Pitscotte at the fording point. Meanwhile Charles and Hamilton sat in reserve in the city. Charles set up his command post within the Cathedral itself. 
The 3rd of September marked the start of the battle. At around 6 o’clock, the parliamentarians Fleetwood and Lambert began their advance to the fording place, defended by Pitscotte, whilst the parliamentarian Deane and three regiments advanced towards Powick Bridge. Both sides of the battle clashed at similar times and brutal fighting ensued. Meanwhile Cromwell had used his guile and cunning to create a bridge of boats to cross the Severn just north of Pitscotte’s position. Cromwell crossed the Severn here and outflanked Pitscotte’s forces, forcing a retreat. 
Powick Bridge was where the majority of the violence occurred. Keith’s smaller force held out against the larger parliamentarian regiments for some hours, however one of the new model army’s cavalry units forded the river and charged the rear of Keith’s force, forcing a retreat also. Despite this, the battle continued for some hours more, the Scots held a solid defence along the hedgerows and fields between Worcester and the River Teme. Only by ‘push of pike’, as one parliamentarian soldier described it, did the royalists and Scots retreat to the city, marking the beginning of the end of the battle. Parliamentarian forces reached Fort Royal outside Worcester and turned the guns in on the city, bombarding Worcester, destroying buildings and morale. The Scottish commander Hamilton, lead a valiant charge against reserve regiments in Perry Wood to the south-east. However Hamilton suffered a mortal wound and died later in the Commandery building in Worcester, now turned into a museum in recognition of the events of 1651. Charles, in realisation that the battle was lost, retreated from Worcester; after 12 hours of fighting the Scottish forces were forced to surrender to Cromwell, to which end Cromwell dubbed the battle his ‘Crowning Glory’. 
Results of the battle
The end of the Battle of Worcester signified the end of the third civil war in England and Scotland. Cromwell rose to leadership and led the country for seven years under a puritan government. The Scottish army was severely weakened by the defeats at Dunbar, Inverkeithing and Worcester, subduing Scottish threats from the north for several years until the Scottish forces were able to recuperate.  The battle itself claimed the lives of 2,000 Scots, with 10,000 captured. Cromwell claimed that only 200 parliamentarians lost their lives during the battle. Worcester was an extremely brutal and violent battle. 
The odds were stacked against the royalists form the beginning. The Scottish and royalist soldiers were exhausted from the journey from Scotland to Worcester, with many suffering from dysentery. The royalist force lacked the crucial artillery support that was an integral part of 17th century tactics and warfare. Scottish forces were several hundred miles from home, with little desire or sense of urgency to fight. The parliamentarians outnumbered the royalists with their better trained, better equipped new model army with sufficient artillery support, not to forget the ingenious and cunning military mind of Oliver Cromwell. 
 The impact of the English civil war by John Morrill, Collins and Brown 1991
 British Battlefields by David Clark, Robinson 2015
 A Discourse of Military Discipline by Gerat Barry 1634
 Battle of Worcester by J.W Willis Bund 1913
 Worcester 1651 by Dr. Richard Holmes Mercia Publication Ltd. 1985
 Charles II by Ronald Hutton, Oxford University press 1989
 The Battle of Worcester, 1651 by Tony Spicer 2002
 Artillery through the Ages by Albert Manucy 1949
 Cromwell’s Crowning Mercy by Malcolm Atkin, Sutton Publishing 1998