1. First Battle of Lostwithiel, 1642
2. Second Battle of Lostwithiel, 1644
From his HQ in Oxford, he marched west in pursuit of Robert Devereux, 3rd Earl of Essex, who was invading the Royalist stronghold of Cornwall. Charles's army vastly outnumbered that of Devereux, and had the advantage of surprise. On September 2 1644, Charles's army attacked the rear of Essex's force and quickly surrounded it at Lostwithiel, 30 miles west of Plymouth, attacking from both the north and the east at the same time. Lostwithiel was strategically important during the English Civil War since it held the key to Fowey, at the time a major seaport.
Devereux and most of his cavalry managed to escape, but virtually all of the infantrymen, about 8,000, and the artillery fell into the king's hands. Only Major-General Philip Skippon and a few of his men succeeded in fighting their way out. Charles wheeled about and marched toward London.
This setback for Parliament in Cornwall, and the last major victory for the Royalists, was reversed by Sir Thomas Fairfax leading the New Model Army at or near Tresillian Bridge, close to Truro on March 12 1645.