On 20 September, 1745, Sir John Cope's forces encountered Prince Charles Edward Stuart's advance guard near Prestonpans. He drew up his army facing south with a marshy ditch to their front, the park walls around Preston House protecting their right flank and the sea to his rear. He mounted his cannon behind the low embankment of the Tranent colliery waggonway which crossed the battlefield.
The Jacobite army secured the high ground around Tranent to the south of Cope's army but were dismayed by the natural advantages of Cope's position. A frontal highland charge would flounder in the marshy ground in front of the Government army and would be cut down by musket and cannon fire.
Robert Anderson was a local farmer's son who knew the area well and he managed to convince the Jacobite command that he knew an excellent route through the extensive marshlands to the Government army’s open left flank. Following his advice, the entire Jacobite force set off at 4 am on a flanking march, walking three abreast along the unguarded Riggonhead defile, far to the east of Cope's position. In total silence, they arrived to the east of Cope's army at Seton West Mains. Although Cope had kept fires burning and had posted pickets during the night as the Highlanders were making their move they were not spotted by the pickets until around 5 a.m. The estates of Bankton House and Preston House, Preston House and Northfield House can be identified in the painting.