It is a Grade I listed building and is notable both for the range of its architecture and for being the site of the concluding action of the Battle of Alton during the English Civil War.

[2] At the top of the pillars supporting the arches are designs fashioned by French craftsmen with axes,[2] including a wolf eating a bone (pictured, below left), a pelican, several winged cherubs, a demon and a pair of donkeys.

[8] The 15th century saw a great number of extension and additions to St Lawrence's, including: the new northern nave – this was of roughly the same proportions as the existing southern nave, and made the church, in Pevsner's words, "essentially a parallelipiped [sic]";[3] what was previously the north wall to the old church was demolished and seven arcades were installed in its place, with three paintings of saints (pictured, left) remaining on the northern side of the second pillar from the west; new roofs over both naves; windows recast in the Perpendicular style; carved screens to choir and altar, and rood screen; a spire on top of the old tower.

[9] The exterior of the church (apart from the Victorian broach-spire) also dates from the 15th century,[3] and is fashioned from local flint and stone covered with plaster.

The royal licence for the building of this chapel was issued on 20 October 1463: Sir Maurice Berkeley, Sir John Parre, Hugh Crikland, perpetual vicar of Alton, and others, to found a chantry of one chaplain to celebrate daily in a chapel lately built by John Champfloure in the said parish church.

[11] It appears that in this period the church was also a seat of learning; with the exception of Winchester College, the oldest record of any educational establishment in Hampshire comes from a report of 1548 to Edward VI's Chantry Commissioners, which states that there was in Alton: a stipendiary Priest, founded by one John Chanflower, to have continuance for ever, to the intent to assist ministration in the Church of Alton and to teache children grammer.

Further building work occurred in the 16th century – the south door and porch, a priest's entrance to the Lady Chapel (made by the vicar Ralph Herriott; his initials may be seen on it)[12] – but it is only in the 17th century, again in Couper's words, that the church "steps into the full light of day",[13] with an instruction of Elizabeth I to the local JPs that the Poor Law provisions are being implemented, the beginning of the parish registers in 1615 and the churchwarden's accounts in 1625.

"[14] According to Tony MacLachlan: For the Royalists, the fighting was just a splendid gesture of defiance, meaningful, spirited and dignified, but hopeless.

But the pressure of the distressed outside forced the doors open again, and the last of the sanctuary seekers went inside.After a concerted assault, during which, according to the Parliamentarian Lieutenant Archer, "the churchyard was full of our men, laying about them stoutly with halberts, swords, and musket-stocks, while some threw hand-granadoes in at the church windows,"[15] the Parliamentarians eventually broke through the west door of the church, and Colonel Boles, who had threatened to kill any of his soldiers who asked for quarter,[17] was killed – the traditional place given for his death was on the steps of the pulpit.

A facsimile of a tablet at his tomb in Winchester Cathedral (and containing the same mistakes – the date of the battle, for instance, is given as 1641), it states in part: Alton will tell you of that famous Fight Which y man made & bade this world good night His verteous Life fear'd not Mortalyty His Body must, his Vertues cannot Die Because his Bloud was there so nobly spent This is his Tombe that Church his Monument.

According to an eye-witness account: On Sunday when the Reverend Minister of the parish was towards the latter end of Prayer before Sermon, it grew on a sudden so exceeding dark that the People could hardly discern one another, and immediately after happened such flashes of lightning that the whole Church seemed to be in a bright flame; the surprise of the Congregation was exceeding great, especially when two Balls of Fire made their entry at the Eastern Wall, pass'd through the body of the Church, leaving behind 'em so great a Smoke, and Smell of Brimstone as is scarce able to be expresst.

[20]All of the church's windows were broken, the roof and steeple were badly damaged after being set on fire, the tower had a hole blasted through it and the weathercock, according to the same eye-witness, "was carried quite away, and the hand and Boards belonging to the Clock fell among the Congregation.

[22] In 1742 the plain window on the northern wall behind the pulpit was replaced "with a Square Crown Glass in order to give it better light, and also to alter the Sounding Board in such a manner as shall be thought most proper upon the opinion of the Revd.

[23] The charitable works undertaken by the church are also meticulously detailed; this was the era in which charitable trusts were set up, and we find that John Fisher made a gift of £8 in 1741, which was "as an annual allowance for three sermons to be preached in Alton Church on the Anniversary of his death, and for a distribution of bread and money to the Poor of Alton.

[24] John Murray, the founder of the Universalist denomination in the United States, was born in 1741 in Alton and baptised in St Lawrence's.

Murray's Life gives an account of the customs surrounding baptism at St Lawrence's: I was hardly two years old, when I had a sister born; this sister was presented at the baptismal font, and, according to the custom in our Church, I was carried to be received, that is, all who are privately baptized, must, if they live, be publicly received in the congregation.

The congregation were astonished, and I have frequently heard my parents say, this was the first word I ever uttered, and that a long time elapsed, before I could distinctly articulate any other.

But the greatest want is that of suitable accommodation for the Working Classes ... A Plan and Estimate have been obtained from an experienced Architect for removing all the present galleries, adding a North Aisle and Western Gallery to the Church, and Re-pewing the whole, so as to yield increased accommodation for 200 persons, and to make the Sittings generally suitable and convenient.

[29] The most notable addition was an organ, paid for by public subscription (at a cost of £850[30]), and built by Messrs Speechly and Ingram.

The clock in use today was installed in 1890 by Messrs J. W. Benson; a Mrs Gerald Hall started its mechanism at 12 noon on Saturday 7 June 1890.

[30] The window to the north of the high altar (1899) depicts the archangels Gabriel, Michael and Raphael; it was dedicated to Henry Hall (the brewer).