cond lieutenant in the royal engineers in January 1797, and was promoted to be first lieutenant on 29 Aug. 1798.
In August 1799 Squire embarked with the expedition under Sir Ralph Abercromby [q. v.] for the Helder. He took part in the affair of 10 Sept., when he was wounded. He was also in the actions of Bergen and Alkmaar on 2 and 6 Oct. He returned with the army to England at the end of October.
In 1801 he went to Egypt, and served throughout the campaign in that country under Abercromby and under General (afterwards Lord) Hutchinson. He was present at the battle of Alexandria on 21 March, the capture of Rosetta on 8 April, the capture of Fort St. Julien after a three days' siege on 19 April, the siege of Alexandria in August, and its capitulation, after an armistice of some days, on 2 Sept. During his stay in Egypt, in conjunction with Captain William Martin Leake [q. v.] of the royal artillery and William Richard Hamilton [q. v.], he deciphered the Greek inscription on the so-called Pompey's pillar at Alexandria.
On the conclusion of the Egyptian campaign Squire obtained leave of absence, and, in company with Leake and Hamilton, made a tour through Syria and Greece. On leaving Athens for Malta in the brig Mentor, laden with some of the Elgin marbles, Squire's party was wrecked on the island of Cerigo on 17 Sept. 1802, and narrowly escaped death. By strenuous exertions many of the marbles and some of the journals, plans, and papers were recovered. Wherever Squire travelled he kept a full and accurate journal. On his arrival home, early in 1803, Squire and Leake presented to the Society of Antiquaries a memoir on Pompey's Pillar, which was read on 3 Feb. by Dr. Raine of the Charterhouse, who had suggested characters to replace the eighteen which were entirely obliterated (Archæologia, vol. xv.).
Squire was promoted to be captain lieutenant in February 1803, and second captain on 19 July 1804. He was employed in the southern military district on the defences of the coast of Sussex. On 1 July 1806 he was promoted to be first captain, and appointed commanding royal engineer in the expedition to South America. He accompanied Sir Samuel Auchmuty to the La Plata, landing in January 1807. Squire conducted the siege operations at Monte Video, which, on a practicable breach being made, was carried by storm on 3 Feb. He was also commanding royal engineer under Major-general John Whitelocke [q. v.] in the operations from 28 June to 5 July which culminated in the disastrous attack on Buenos Ayres and the humiliating terms by which Monte Video was given up, and the expedition returned to England. Although Squire received the best thanks of Whitelocke in his despatch, he bore witness for the prosecution at the court-martial held in London in March 1808.
In April 1808 Squire accompanied Sir John Moore's expedition to Sweden, and in the summer went with that general's army to Lisbon, taking part in all the operations of the campaign, which terminated on 16 Jan. 1809 in the victory of Coruña. He embarked the same night with the army for England, arriving in February. In April he was sent by Lord Castlereagh in a frigate on a secret mission to the Baltic, to report on the defences and importance of the island of Bortholm as a defensive naval station.
On 28 July of the same year he sailed, as commanding royal engineer to Sir John Hope's division, with the army under the Earl of Chatham to the Scheldt. On 30 July he reconnoitred with Captain Peake, R.N., the channel and shores of the East Scheldt. He took an active part in the siege of Flushing, and was present at its capture on 14 Aug., returning to England in December.
In 1810 Squire published anonymously ‘A Short Narrative of the late Campaign of the British Army, &c., with Preliminary Remarks on the Topography and Channels of Zeeland’ (2nd ed. same year). The work is a careful study of the geography and history of the campaign, and contains not only outspoken criticisms on its conduct, but concludes with an able exposition of operations which might have been adopted with success.
On 28 March 1810 Squire joined Wellington's army in Portugal. He was at once employed in the lines of Torres Vedras, and on their completion was, in October, appointed regulating officer of No. 3 district, from Alhandra to the valley of Calhandrix. On the retreat of Masséna in March 1811, Squire accompanied Marshal Beresford's corps to the relief of Campo Mayor on 25 March. At the end of March his resource in constructing bridges across the Guadiana and making a breach in the defences of Olivenza materially contributed to the capture of that place on 15 April. His services were equally great at the two sieges of Badajoz (5–12 May and 25 May–10 June), and on both occasions Wellington mentioned him in his despatches.
On 21 June 1811 Squire was attached to Lieutenant-general Sir Rowland Hill's corps in Estremadura. He took part in the battle