John Armstrong was born on 31 March 1674 in the village of Ballyan, in what is now County Offaly in Ireland. He was the eldest son of Robert and Lydia Armstrong, originally from the Scottish Borders and distantly related to the notorious reiverJohnnie Armstrong. He had two sisters, Lydia and Elizabeth ; his brothers Samuel and Michael also served in the army. In 1710, he married Anna Burroughs and they had five daughters, Lydia, Anne, Frances, Mary and Priscilla.
Career
The 1688 Glorious Revolution sent James II into exile and in an attempt to regain his kingdoms, he landed in Ireland in March 1689, launching the Williamite War in Ireland; in 1691, Armstrong joined the Duke of Ormonde's Horse Guards, part of the Williamite army. Captured by Jacobite forces, he was released when the war ended with the October 1691 Treaty of Limerick and in 1695, he enrolled in his relative Philip Armstrong's troop, part of Wood's Regiment of Horse, later 3rd Dragoon Guards. After the Nine Years War ended with the Treaty of Ryswick in 1697, the regiment returned to England. At the start of the War of the Spanish Succession, he served at Cadiz under Ormonde, who recommended him to Holcroft Blood, Marlborough's chief engineer. Armstrong served in the Flanders campaign, including Blenheim in 1704 and the Siege of Bouchain in 1711. He worked with fellow engineer and long-time acquaintance Thomas Lascelles and they remained close colleagues until Armstrong's death in 1742. He managed to retain his positions through the political struggles of 1712-1715 and was appointed Quartermaster-General to the Forces just before the war ended with the 1713 Peace of Utrecht. The treaty included the provision that France 'level the fortifications of Dunkirk, block up the port and demolish the sluices that scour the harbour, shall never be reconstructed.' For decades before and after, Dunkirk was a major privateer base for raiding British merchantmen, since it was possible to reach the North Sea in a single tide and escape Royal Navy patrols in the Channel. This made it a high profile operation of great significance to the powerful London mercantile interest and in September 1713, Armstrong and his colleague Thomas Lascelles were appointed to supervise operations. After the accession of George I in 1714, Marlborough was restored as Master-General of the Ordnance and initiated a series of reforms. Armstrong became Chief Royal Engineer, with his predecessor Michael Richards as Surveyor-General of the Ordnance; on his recommendation, the Ordnance Service was divided in 1716 into artillery and sappers or engineers, later the Royal Engineers and the Royal Artillery. In May, Armstrong was at The Foundery in Moorfields watching a demonstration of captured French cannon being recast when an explosion killed 17 of the 25 people present; he was one of the very few to escape injury and the accident led to the institution of the Royal Arsenal in Woolwich. He returned to England in 1718 with Lascelles taking over at Dunkirk; in addition to his official duties, he was involved in multiple activities, becoming a Fellow of the Royal Society in May 1723. His proposals for improving port facilities at King's Lynn were included as an appendix to Thomas Badeslade's 1725 work 'History of the ancient and present state of the navigation of the port of King's Lyn.' In the 1720s, he designed and constructed a lake at Blenheim Palace, later replaced by a Capability Brown feature. He was closely involved in setting up the Royal Arsenal and Royal Military Academy, Woolwich, served as Colonel of the Royal Regiment of Ireland from 1735 to 1742 and promoted Major-General in 1739. Late in 1741, he was taken ill at his office in the Tower of London where he died on 15 April 1742; he was buried in the chapel attached to the Tower, the Church of St Peter ad Vincula.
