In 1688 he left the Danish service, on account of "some injustice done him in his promotion", and went to Poland as a volunteer; but he was offered a commission in the Prussian Guards, which he accepted.
In 1692 he left the Prussian army, with a commission to raise a regiment for the emperor; but failing in this design, he went in April to the camp of Louis XIV before Namur.
But Borgard, a sturdy Protestant, refused the tempting offer, and joined Colonel Gore, whose acquaintance he had made at Bonn, as a volunteer.
Albert Borgard died at Woolwich, where he was living, on 7 February 1751 and was buried in the Danish church in Marine [Wellclose] Square, near the Tower of London.
Though but thirty-three years of age when he joined the English army, he had been present at eleven battles and twelve sieges, and was one of the most experienced artillery and engineer officers in the world.
Gore introduced him to William III, who saw his ability, and made him a firemaster in the English service in 1693, and captain and adjutant of the artillery in Flanders in 1695.
When at the peace of 1697 all the foreign artillerymen in English pay were dismissed, he, with only one other officer named Schlunt, was taken to England, and in 1698 made an engineer by William III's special command.
His honourable behaviour as colonel-commandant is noted in a letter of his nephew, Major-General Albert Borgard Michelsen: "He was strictly honest, and declared often, and shortly before he died, that he could safely affirm it upon oath that he had never made 6 pence out of his regiment above what the king allowed, and gave up the cloathing of the regiment to the Board of Ordnance, that he might not be suspected to have any profit of it...
When he died at Woolwich, on 7 February 1751, at the great age of ninety-two, he left to his successor, General Belford, one of the finest corps of artillery in the world.