The Battle of Y Dalar Hir took place on 5 June 1648 in Caernarfonshire, North Wales, during the Second English Civil War. While little more than a skirmish, it had a significant effect on the local progress of the conflict.
Leading Welsh Royalist Sir John Owen of Clenennau mustered a group of 250-300 cavalry and foot in an attempt to raise North Wales in rebellion against Parliament; on 3 June he defeated local militia in a skirmish near Caernarfon and besieged Caernarfon Castle. Colonel George Twisleton, Parliamentarian governor of Denbigh, confronted Owen at Y Dalar Hir on the shore of the Menai Straits near Llandegai, where the Royalists were scattered and Owen captured, effectively ending the spread of the rebellion in North Wales.
Background
The First English Civil War had ended in 1646 with the defeat of Charles I's forces, but by 1648 divisions within Parliament and the army were threatening peace. Believing himself essential to any peace settlement, Charles had refused to compromise in negotiations; in December 1647 he made an agreement with representatives of the Scottish Parliament to restore him fully to the English throne in return for imposing a Presbyterian polity for three years. He expected backing from Presbyterian moderates in the English Parliament, while mutinous elements of the army also became drawn into the plan.
The revolt began in Pembrokeshire, an area controlled by Parliament since early 1643. Like their colleagues in the New Model Army, the soldiers had not been paid for months, and feared being disbanded without their wages. In early March, John Poyer, Governor of Pembroke Castle, refused to relinquish command; he was joined by the senior commander in South Wales, Rowland Laugharne.
What began as a pay dispute became overtly political when the Welsh rebels made contact with Charles. Most Royalists had sworn at the end of the first war not to bear arms against Parliament and did not participate, one exception being Sir Nicholas Kemeys, who held Chepstow Castle for the king. By the end of April, Laugharne had assembled around 8,000 troops, and was marching on Cardiff.
In the interim Royalist sympathisers attempted to expand the revolt into North Wales. The north had been affected by the same pay issues as South Wales, while heavy taxation and a poor harvest in 1647 stoked local economic resentments. At the beginning of May, Sir John Owen, a Caernarfonshire landowner who had served as Royalist governor of Conwy Castle during the first war, began recruiting in Merioneth. Senior Royalist exile John Byron, who in March had been given a commission to raise men in his former command of North Wales by the Prince of Wales in anticipation of a Scots intervention, left France for Anglesey on hearing of Owen's mobilisation. While small numbers were involved, Byron believed a guerrilla-type campaign in the north could assist the Pembrokeshire rebels by drawing away Parliament's resources.
On arrival at Anglesey Byron found most local landowners unenthusiastic, but he and Owen continued recruitment efforts throughout May, "giving out many threatening speeches against the Parliament". In the south, Laugharne was defeated on 8 May at St Fagans, but the Royalists' retention of several fortresses encouraged them to continue. The garrison of Beaumaris under Captain Thomas Symkys joined the revolt, as did elements of the Anglesey Trained Bands. In mid-May Owen was reported at Dolgellau with about "100 reformados [former Royalist officers] where they quartered two nights"; Colonel George Twisleton at Denbigh sent patrols to search for Owen among the mountain passes, but the Royalists managed to evade them. The counties of Flintshire, Denbighshire and Montgomeryshire issued declarations that they would resist the rebels and "oppose [...] the disturbance of the peace of the Kingdome".
Skirmish at Caernarfon
By the beginning of June Owen had raised a force of about 300. Thomas Mytton, governor of Caernarfon and senior Parliamentarian commander in the area, was anxious to crush the rising before it grew further and sent an urgent message to Twisleton at Denbigh requesting reinforcement. Twisleton and John Carter, governor of Conwy, gathered a scratch force of less than 200 men from Chester and their own garrisons and set out to relieve Mytton, dragging two small field guns with them.
On 3 June Owen clashed at Llandwrog with local militia under Mytton and William Lloyd, Sheriff of Caernarvonshire. Lloyd was seriously wounded and taken prisoner, while Owen briefly besieged Mytton in Caernarfon Castle; Mytton grew concerned that more sympathisers might join the Royalists after hearing news of Owen's success.