Destining him for the profession of arms, he had him educated with the greatest care, and in his nineteenth year enrolled him as a cadet in the Legion of Maillebois, which was to enter Holland, and second a revolution there--a movement neutralized by the influence of Prussia. In 1784 young Macdonald was appointed a Sub-lieutenant in Dillon's Regiment, a battalion of the Irish Brigade, which now included in its rank many Scottish emigrants and their descendants; and in this corps he remained a subaltern until the Revolution in 1792, when his colonel, the brave, loyal, and unfortunate Dillon, was murdered at Lisle, where his body was literally torn to pieces by the revolted soldiers and infuriated mob. Although, like the 4th Hussars and the Regiment of Berwick, Dillon's battalion emigrated entire and joined the fugitive French princes, Macdonald remained in France; _not_ because he did not share the loyal sentiments of his comrades, but because he loved the beautiful Mademoiselle Jacob, whose father had joined the popular party against the monarchy. This lady he afterwards married; and the influence of her family led him to embrace, or at least to adopt, the principles of the revolutionists, while he avoided their crimes and excesses. The new government soon discovered that Macdonald was a bold, active, and intelligent officer, and at once gave him employment. He made the first campaign of the revolutionary war as Staff-major, under de Bournonville, and served afterwards in the same capacity with General Dumourier, acquitting himself so much to the satisfaction of these distinguished leaders, that, on the 1st of March, 1793, he was appointed Colonel of the Regiment de Picardie, the second regiment of the old French line, which was then in garrison at Thionville; and this ancient corps (which was originally raised by Charles IX. in 1562) he commanded in the first campaign in Belgium. He was sincerely attached to Dumourier; but, on the defection of that general from the Republic, after his fruitless attempts on behalf of the king, his retreat to the camp at Maulde, and the attempt to assassinate him on the 5th April, Macdonald did not accompany him in his flight to the Austrians, but remained with the army, in which he was soon after named a General of Brigade. Under the celebrated Pichegreu he served with this rank in the Army of the North against the combined forces of Britain and Austria, and particularly signalized himself at Werwick and Comines.