Siege of Hull ( 1643 ) The unsuccessful second Siege of Hull by the Royalist Earl of Newcastle in 1643 was a victory for Parliament at the high point of the Royalist campaign in the First English Civil War . It led to the abandonment of Newcastle ' s campaign in Lincolnshire and the re - establishment of Parliament ' s presence in Yorkshire . Prelude . The Lincolnshire Campaign . After the victory over the army of Parliament under Lord Fairfax and Sir Thomas Fairfax at the Battle of Adwalton Moor on 30 June 1643 , the Earl of Newcastle advanced with the main northern Royalist army into Lincolnshire . At this point in the Civil War , Royalist fortunes were high , and Newcastle ' s advance joined Lord Hopton ' s and King Charles ' armies in a three - pronged advance on London . Gainsborough and Lincoln . On 16 July 1643 , Lord Willoughby captured Gainsborough for Parliament , only to be immediately besieged by the Royalists under Sir Charles Cavendish . Parliament sent a relieving force under Sir John Meldrum and Colonel Oliver Cromwell , which beat the Royalists at the Battle of Gainsborough on 28 July . However , the arrival of Newcastle ' s main army forced the abandonment of Gainsborough , which , with Lincoln , fell quickly to the Royalists . The Fairfaxes . The Fairfaxes , meanwhile , having escaped from Adwalton Moor made their ways separately to Hull , then the only remaining Parliamentary stronghold in Yorkshire . Sir John Hotham , the Military Governor of Hull , was arrested and removed by Major - General Robert Overton and the people of Hull in July 1643 after conspiring with Newcastle to surrender the city . Lord Fairfax was invited to take up the post by the townsfolk of Hull on 22 July . He fortified Hull , established a base at Beverley , and set about vigorous raids on Royalist garrisons in Yorkshire . Newcastle now faced a choice . He had Boston and the Eastern Association apparently open in front of him , but faced the prospect of the still - intact army of Lord Fairfax behind him in Hull . Fairfax ' s attack on Stamford Bridge , near York , prompted Newcastle that he must deal with this threat to his rear , and he turned his army back north to face Fairfax , leaving garrisons in the captured Lincolnshire towns and strongholds . Beverley . Newcastle advanced with 12 , 000 foot and 4 , 000 horse , together with his siege train including the guns " Gog " and " Magog " . Fairfax ' s force of 1 , 800 foot and 20 troops of horse , decided to retreat to the fortifications of Hull . Beverley was abandoned on 28 August , and occupied by the Royalist army , where Within the week , Fairfax ' s army was back in Hull . The Siege . Newcastle ' s army followed closely , occupying the villages around Hull , and began to construct siegeworks for the investment of the city . The Royalist siege artillery began the bombardment on 2 September , but without great effect because the works were too far away from the city walls , the shot being almost spent by the time it reached the city . The Royalists attempted to push their earthworks nearer to make their guns more effective . However , one such work , Fort Royal , was taken by the defenders and destroyed within a week of construction . On 14 September , Fairfax ordered the sluices be opened and the banks of the Humber be broken , as had happened in the first siege of Hull in 1642 . This flooded the surrounding land to a distance of two miles . The Parliamentary warships " Lion " ( captained by Thomas Rainsborough ) and " Employment " arrived to control the Humber estuary and bring in supplies . On 22 September , Cromwell crossed the Humber from Lincolnshire with arms and ammunition for the defenders , and joined the Fairfaxes in the defence of the city . Four days later on 26 September , Sir Thomas Fairfax ferried his dragoons and cavalry back across the Humber to join the Eastern Association forces in Lincolnshire . Sir John Meldrum brought 500 further reinforcements to the defenders . On 9 October , the Royalists attempted to storm the defences . Although some outlying works were captured , the assault failed to seize the city . The defenders launched a counterattack two days later on 11 October , with 1 , 500 men comprising soldiers from the garrison , sailors from the warships and townspeople . Led by Meldrum , the force was divided into two columns under Colonel John Lambert and Colonel Thomas Rainsborough of the " Lion " . This attack pushed back the Royalists and captured several emplacements and heavy guns . Aftermath . On 12 October , Newcastle admitted defeat and lifted the siege . He withdrew to York . The lifting of the siege was marked by an annual public holiday in Hull until the Restoration . On 11 October , the Royalists had been defeated at the Battle of Winceby in Lincolnshire . These two defeats ended Royalist hopes of advancing on London and threw them on the defensive . The Parliamentarians began their advance into Yorkshire that was to culminate with Newcastle being besieged in York and the consequent Battle of Marston Moor .