In 1762, he bore a colonel's commission, and served under Brigadier-general Burgoyne in Portugal, where he was intrusted with an enterprise against a Spanish post at the old Moorish castle of Villa Velha, on the banks of the Tagus. He forded the river in the night, pushed his way through mountain passes, and at 2 o'clock in the morning, rushed with his grenadiers into the enemy's camp before daylight, where every thing was carried at the point of the bayonet, assisted by a charge of dragoons. The war over, he returned to England, bearing testimonials of bravery and good conduct from his commander-in-chief, the Count de la Lippe, and from the king of Portugal. [Footnote: Life of Charles Lee, by Jared Sparks. Also, Memoirs of Charles Lee; published in London, 1792.] Wielding the pen as well as the sword, Lee undertook to write on questions of colonial policy, relative to Pontiac's war, in which he took the opposition side. This lost him the favor of the ministry, and with it all hope of further promotion. He now determined to offer his services to Poland, supposed to be on the verge of a war. Recommendations from his old commander, the Count de la Lippe, procured him access to some of the continental courts. He was well received by Frederick the Great, and had several conversations with him, chiefly on American affairs. At Warsaw, his military reputation secured him the favor of Poniatowsky, recently elected king of Poland, with the name of Stanislaus Augustus, who admitted him to his table, and made him one of his aides-de-camp. Lee was disappointed in his hope of active service. There was agitation in the country, but the power of the king was not adequate to raise forces sufficient for its suppression. He had few troops, and those not trustworthy; and the town was full of the disaffected. "We have frequent alarms," said Lee, "and the pleasure of sleeping every night with our pistols on our pillows." By way of relieving his restlessness, Lee, at the suggestion of the king, set off to accompany the Polish ambassador to Constantinople. The latter travelled too slow for him; so he dashed ahead when on the frontiers of Turkey, with an escort of the grand seignior's treasure; came near perishing with cold and hunger among the Bulgarian mountains, and after his arrival at the Turkish capital, ran a risk of being buried under the ruins of his house in an earthquake.