Through the Napoleonic Wars, county cricket virtually died as cricket was impacted by losses of investment and manpower.

Impact of the Napoleonic Wars With no national competition in place, there were few senior matches in the 18th and early 19th centuries. Even so, there is a noticeable difference between the number played each season in the 1790s and the handful per season of the 1800s and, much less, the 1810s. The ACS in its Important Matches guide has listed more than twenty in 1795, a time of stalemate in the French Revolutionary Wars; but only six in 1805, the year of the Battle of Trafalgar; and then just three for the whole period from 1811 to 1813 when British forces were heavily involved in the Peninsular War. Nevertheless, the impact of this war was less severe than that of the Seven Years' War because of the existence this time of MCC and other well-organised clubs like Brighton and Montpelier. These clubs managed to co-ordinate cricket activities through the war and, as it were, keep the game going.

In 1803, William Pitt referred to cricket when the Commons debated the Defence Bill that was later passed into law as the Defence of the Realm Act 1803. Pitt was then the effective Leader of the Opposition to the Whig government of Henry Addington. One of the Act's key requirements was that local authorities must list able-bodied men aged fifteen to sixty, and classify them in terms of fitness for military service. As increasing numbers of young men entered service, cricket went into decline and, on 17 September 1813, the Nottingham Review said: "The manly and athletic game at cricket for which the boys of Sherwood have been so long and so justly famed, it was thought, had fallen into disuse, if not disgrace...." Also, there is a view expressed by Rowland Bowen that the game had gone out of fashion in addition to the wartime problems it faced.

The first cricketer known to have died on active service was Richard Beckett of Leeds, whose senior career spanned the 1804 to 1807 seasons. He joined the Coldstream Guards and, as a captain, was killed at the Battle of Talavera on 28 July 1809.

A discernible recovery began in 1815 as the Napoleonic Wars ended after the Battle of Waterloo on 18 June. Six senior matches have been recorded from that summer and the first centuries were scored at the new Lord's ground in St John's Wood. The centuries were scored in the Middlesex v Epsom match on 24 & 25 August by Felix Ladbroke and Frederick Woodbridge who scored 116 and 107 respectively for Epsom.

Among debutants in 1815 was Algernon Greville, better known as the Duke of Wellington's private secretary from 1819. Greville fought at Waterloo as an ensign. He played in seven senior matches until 1823.

MCC and Lord's Old Ground Marylebone Cricket Club (MCC), based at Lord's Old Ground until 1810, continued to play the leading role in the sport. Several matches of the 1800s involved the more prominent town clubs such as Homerton, Montpelier, Richmond and Woolwich.

By the 1800s, Lord's Old Ground was already losing its rural character as London expanded and began to surround it. The landowning Portman Estate felt able to increase the rent and so Thomas Lord decided to seek another venue. The lease on the Old Ground was due to expire on Lady Day (25 March) in 1810 but Lord moved fast and, by May 1809, had secured a lease on another plot of land, part of the St John's Wood estate which belonged to the Eyre family. The match in August 1810 between Captain Blagrave's XI and Colonel Byng's XI is the last known to have been played on Lord's Old Ground.

Middle Ground Lord opened his "Middle Ground" in time for the 1809 season but MCC at first refused to relocate. The Middle Ground was used by St John's Wood Cricket Club while MCC continued to play at the Old Ground. In the winter of 1810–11, Lord staged a fait accompli by seizing "his turf" which was dug up and moved to the Middle Ground. Despite the opposition voiced by some members, MCC were obliged to follow.

Records of only three senior matches have been found for the years 1811 to 1813 with the war taking an increasing toll of cricket's manpower and investment. All were played at the Middle Ground and are the only known senior matches played there. Benjamin Aislabie's XI v George Osbaldeston's XI at the Middle Ground on 8–9 July 1811; Lord Frederick Beauclerk's XI v George Osbaldeston's XI at the Middle Ground on 15–17 June 1812; and Lord Frederick Beauclerk's XI v Edward Bligh's XI on 7–9 June 1813 – this was the last senior match known to have been played on the Middle Ground. James Rice played in all three and they are the only ones he is known to have played in.

In 1813, the site of the Middle Ground was requisitioned by Parliament for construction of the Regent's Canal. Lord contacted the Eyre Estate and persuaded them to lease him another parcel of land in St John's Wood, about half a mile further north at a place called North Bank. This site had previously been a duckpond.

Lord's – the current ground In the winter of 1813–14, Lord again had his turf dug up and removed. He built a high perimeter fence, a tavern and a pavilion at what became the current Lord's ground. On 22 June 1814, MCC played the first match at Lord's against Hertfordshire, then as now a minor county team. The first match of importance at Lord's was played 13–15 July 1814 when MCC hosted St John's Wood CC, whose team included a number of Surrey county players. St John's Wood CC was incorporated into MCC soon afterwards.

MCC – influence and controversy By 1816, the new Lord's had become cricket's feature venue and MCC was gradually increasing its influence and control. It made efforts to suppress the gambling that had underwritten and sometimes blighted cricket in the past.

But MCC was by no means in full control of events. It was the subject of bitter controversy in the post-war period, largely because of the activities of Lord Frederick Beauclerk, one of the sport's more dubious personalities who effectively "ran" the MCC Committee for many years. There was fierce infighting between Beauclerk and his enemy George Osbaldeston which finally erupted into a match-fixing scandal. In 1817, soon after his unique achievement of scoring two centuries in the same match, it was alleged that William Lambert had "sold" an earlier Nottingham v England match. Nottingham had won the game by 30 runs despite a first innings deficit and many gamblers lost heavily. MCC banned Lambert from Lord's for life. Whether he was actually guilty is questionable as no proper hearing was ever organised. The whole affair may have been contrived by Beauclerk to settle an "old score". After MCC banned Lambert in 1817, his patron Osbaldeston struck his own name from the MCC members list in anger in 1818. He later repented and tried to restore himself but his application was blocked by Beauclerk. Osbaldeston could no longer play at Lord's and that effectively ended his senior career.

In 1822, MCC appointed Benjamin Aislabie as its first honorary secretary (to 1842). Aislabie was a rich wine merchant and the owner of slave-operated plantations in the West Indies.

The crisis of 1825 In 1825, the club almost foundered in the face of a dual crisis. On Thursday, 28 July, a schools match at Lord's between Harrow and Winchester had just concluded. Then, during the night, the pavilion was destroyed by fire with the consequent loss of valuable scorecards, records and trophies. Lord claimed he lost £2,600 in paid subscriptions, none of which were ever recovered. Many irreplaceable documents which recorded early cricket matches are believed to have been lost. The impact of this upon cricket's history is that it is only since 1825 that surviving records can be viewed with anything like complete confidence.

Later that year, MCC members were outraged when Lord proposed to build houses on the land. William Ward, who was a rich banker as well as a good batsman, stepped in and purchased the ground lease of Lord's to save it for cricket.

Also in 1825, Charles James Barnett became the earliest known president of MCC. This is an annual appointment and there may have been earlier presidents but there is no record of them, perhaps because the records were lost in the fire.

Schools and universities The Eton v Harrow match was first definitely recorded at Lord's in 1805 but, according to a Harrovian who played in that match, the fixture also took place in 1804 with Harrow winning. Lord Byron played for Harrow in 1805.

On 30 May 1817, Cambridge University played Cambridge Town Club at Parker's Piece, Cambridge, the first recorded instance of a fixture which became almost annual until the 1860s and the earliest match involving either team. There was a very fine line between Cambridge Town Club and the later Cambridgeshire County Cricket Club, the one dovetailing with the other.

Noted people William Lambert made his known senior debut playing for Surrey against England at Lord's on 20 July 1801. He became, in Haygarth's words, "one of the most successful cricketers that has ever yet appeared, excelling as he did in batting, bowling, fielding, keeping wicket, and also single wicket playing".

E. H. Budd, who went on to become one of the most famous batsmen of the early 19th century, made his known senior debut in 1802.

Thomas Howard, one of the most outstanding fast bowlers of the underarm era, made his known senior debut on 4–6 July 1803 when he played for Hampshire against a combined Nottinghamshire & Leicestershire team at Lord's.

John Sherman made his senior debut in 1809. His career continued to 1852 and at 44 seasons is the joint-longest on record, equalled only by W. G. Grace from 1865 to 1908.

Jem Broadbridge, who became an outstanding all-rounder in the 1820s, made his known senior debut on 22 July 1814 in a Beauclerk v Osbaldeston match at Goodwood Park.

In 1820, two noteworthy debutants were Fuller Pilch (aged 17) and George T. Knight. Pilch, then of Norfolk, later played for Kent. He is widely held to have been W. G. Grace's predecessor as the greatest-ever batsman. Knight, who was a nephew of Jane Austen, became a prominent member of MCC and played a significant part in the introduction and legalisation of roundarm bowling between 1825 and 1835. He was himself a fast bowler who favoured the roundarm style.

The 1822 debutants included the left-handed batsman James Saunders, noted for his expertise in playing the square cut shot.

Two of the greatest players of the 19th century, bowler William Lillywhite and wicket-keeper Ned Wenman, made their first known appearances in 1825.

Active players, administrators and other contributors of the period included:

William Ashby Charles James Barnett Thomas Beagley Lord Frederick Beauclerk Richard Beckett Billy Beldham Henry Bentley John Bentley Edward Bligh John Bowyer Thomas Boxall Samuel Bridger Jem Broadbridge George Brown E. H. Budd William Capel George Coles Thomas Flavel Charles Greville Algernon Greville Thomas Howard John Hammond Herbert Jenner Douglas Kinnaird George T. Knight Felix Ladbroke William Lambert Richard Leigh Jr George Leycester William Lillywhite Thomas Lord Noah Mann junior Thomas Mellish Mary Russell Mitford George Osbaldeston John Pointer Robert Robinson James Saunders James Sherman John Sherman John Sparks W. Turner Thomas Vigne William Ward John Wells Ned Wenman John Willes Frederick Woodbridge

Achievements In 1805, Lord Frederick Beauclerk became the first batsman known to have scored two centuries in the same season. He made 129* for Hampshire v England in July and 102 for England v Surrey in August.

On 2–5 July 1817, Sussex v Epsom was played at Lord's. William Lambert, guesting for Sussex, scored two centuries (107* & 157) in the match, the first player known to have achieved this feat in an important match.