On thursday the 19th, in the evening, the Chevalier had certain intelligence that G^ll Cope had marched that morning from Dunbar, and was to encamp that night at Haddingtown, upon which he immediately gave orders for the guards of the City to retire early next morning, and he went himself that night to Duddingston....

In obedience to the orders given on the morning of the twentieth the guards retired from the City and joined the army at Duddingston, and brought alongst with them some surgeons, with whom the army was then very ill provided, and some coaches and chaises were likewise ordered for the conveniency of the wounded, so certain was the prospect of a battle, and even a successful one. Thus all things being prepared about nine in the morning, after receiving an exact account of the number of the enemy taken at Haddington, the Chevalier put himself at the head of his small army, drawing his sword, said with a very determined countenance, Gentlemen, I have flung away the scabbard, with God's assistance I don't doubt of making you a free and happy people, Mr. Cope shall not escape us as he did in the Highlands, and then began his march, ordering the few horse, he then had, not above fifty in number, to advance at some small distance in front, and to detach a few to discover the enemy's march. In this manner, with the Camerons in front, he marched in good order, crossing Musselburgh bridge by Pinky park wall. By this time the party of horse sent intelligence that G^ll Cope was nigh to Tranent, from which the Chevalier conjectured that he would engage him on the muir to the west ward of that village, and therefore quickened his march to prevent his gaining the brow of Carberry hill before him, but before he had near reached the top of the hill he was told that Sir John had marched to the left, and posted himself in a low ground betwixt Preston and Seaton. This naturally led him to imagine that he intended to avoid coming to action; and made him determine, if possible, to attack him the same day. With this view he advanced to the hill and drew up his army opposite to G^ll Cope, who was formed in the low ground before mentioned in two lines, with the two regiments of Dragoons on his wings. So soon as the Chevalier had taken a view of the enemy he judged it impossible to attack them in the post they was then in, having a deep ditch in their front which runs along the high road, where he must have sustained great loss before he could pass it; but being determined that at no rate the enemy should give him the slip a second time, he ordered a detachment to take possession of the Church yard which commanded their camp on the left, and as that seemed the only side where it was possible to come at them, he enquired if there was none in the army acquainted with the country to know if the ground would allow him to attack them on the left. There happened to be a gentleman in the army of that county, who told him that there was only one pass on the left whereby not guarded he could come to them, upon which he ordered it to be reconnoitred, and finding it neglected he ordered a detachment of 500 men to be posted upon the high road to the west of Preston to prevent the enemys retiring by that road to Edinburgh, and recalling the detachment from the Church yard he marched his army eastward by the town of Tranent, and drew up in one line opposite to the flank of the enemy, who upon that motion made a half wheel to face him, expecting, as it was imagined, that he then designed to attack them, and which L. G. M—y[88] proposed, as the Highlanders were then full of spirits, and above all things desirous to engage; but the night being then far advanced, the Chevalier thought it better to delay coming to an engagement till next morning, not knowing what might be the consequence of a rencounter in the night should the enemy, if beat, rally and come upon him while in confusion and not able to get his people together, knowing how difficult it was to keep irregular troops together in a body after an action, so resolved to delay it till early next morning, and ordered his army to halt upon the ground about three or four hundred yards from the enemy, and to continue under arms to be ready to march upon a minutes warning.

They accordingly lay close in order of battle the whole night without the least whisper or noise to be heard, while G^ll Cope made some fires in his camp and threw a few shells, which did no hurt. Having continued in this position for some time, he was informed that the detachment of five hundred Atholl men which he had posted upon the west side of the village of Preston had rejoined the army; this made him very uneasy least the enemy had filed off during the night by that road and had taken possession of the City of Edin^r, to prevent which and to intercept the runaways had enduced him to make that disposition. He at first seemed resolved to make them return, but when he reflected that their march, if discovered by the enemy, might induce them to believe it was the whole army, and occasion them to alter their disposition or occasion any confusion or distrust amongst his own people, he judged it safer and better to put up with the disappointment and continue the rest of his plan, tho he could not help complaining that his orders had been neglected in so material a point.

Notwithstanding this faux pas, he kept in very high spirits the rest of the night, laying on the ground without any covering but his plaid, and in the morning, about an hour before daylight, made his army, guided by the gentleman above mentioned, march from the left in three columns, making the left of the first line the right of the army for the attack, which motion, tho perhaps irregular, was yet necessary, and executed with so much order and silence that the small body of horse posted in the rear knew nothing of their march; the officer on duty, either through forgetfulness or that he thought they could be of no service, neglected to give them orders to march. In this order he marched to the enemy, passing a deep bog with out the least observation. The right, composed of the M^cdon^ds of Glengarry and Clanronald, was commanded by the D. of P.,[89] and the left, commanded by L.G.M.,[90] which had made the right the preceding day, consisted of the Camerons and Steuarts of Appin. The third column, which was made up of the Atholl men, was commanded by My L[ord] N[airn]. So soon as the two first columns had passed the bog, they formed and marched straight to the enemy, who by this time had formed and presented themselves in the same order of battle they had appeared the day before. By this time the third column had likewise passed and formed themselves about four score yards in the rear of the first line; rather too near, if the ground would have allowed of a more regular disposition. The left, when pretty near the enemy, finding themselves outwinged, made a motion to front the artillery, which occasioned a gap in the centre, but marching up briskly, they received one fire of the cannon, which did little hurt, and then receiving a fire from the foot, they gave a loud huzza, returning the fire, upon which Gairdner's dragoons run off, and the Highlanders, throwing away their muskets, attacked the foot with incredible impetuosity, who immediately gave ground. Upon the left of the enemy the resistance, if such behaviour merits the name, was much less, for before the D. of P. was within three score yards of them, Hamilton's dragoons began to reel and run off before they could receive his fire; the foot likewise fired too soon, and almost all turned their backs before the Highlanders could engage them with their swords. In a few minutes the rout was total; the dragoons on the right run off by the high road through the town of Preston, and those on the left by the shore towards the east; the few of the foot that saved themselves escaped by Preston Park, the wall of which had been broke down the day before by G^ll Cope's orders. All the baggage of the army was placed in a yard upon the left of their army, guarded by two companies of L. Lowdon's regiment, where so soon as the action was over, Cap^t Bazil Cochran of Coll. Lees[91] was sent by L.G.M. to tell them that if they would immediately surrender as prisoners of war they should be used as such, if not, they would be immediately attacked and no quarter given, upon which they readily gave up their arms.

[88] Lord George Murray.