[9] The Royal Exchange had been founded by English financier Thomas Gresham and Sir Richard Clough on the model of the Antwerp Bourse.

At that coffee house, a broker named John Castaing started listing the prices of a few commodities including salt, coal, paper, and exchange rates in 1698.

In order to regulate these, Parliament passed an Act in 1697 that levied heavy penalties, both financial and physical, on those brokering without a licence.

This limit led to several problems, one of which was that traders began leaving the Royal Exchange, either by their own decision or through expulsion, and started dealing in the streets of London.

Fraud was also rife during these times and in order to deter such dealings, it was suggested that users of the stock room pay an increased fee.

In the Exchange's first operating years, on several occasions there was no clear set of regulations or fundamental laws for the Capel Court trading.

In February 1812, the General Purpose Committee confirmed a set of recommendations, which later became the foundation of the first codified rule book of the Exchange.

In spite of continuous criticism from newspapers and the public, the government used the Exchange's organised market (and would most likely not have managed without it) to raise the enormous amount of money required for the wars against Napoleon.

After the war and facing a booming world economy, foreign lending to countries such as Brazil, Peru and Chile was a growing market.

The constant increase in overseas business eventually meant that dealing in foreign securities had to be allowed within all of the Exchange's premises.

Thomas Allason was appointed as the main architect, and in March 1854, the new brick building inspired from the Great Exhibition stood ready.

Due to fears that borrowed money was to be called in and that foreign banks would demand their loans or raise interest, prices surged at first.

The main concerns included air raids and the subsequent bombing of the Exchange's perimeters, and one suggestion was a move to Denham, Buckinghamshire.

The Exchange's new 321 feet (98 metres) high building had 26 storeys with council and administration at the top, and middle floors let out to affiliate companies.

On 20 July 1990, a bomb planted by the Provisional Irish Republican Army (IRA) exploded in the men's toilets behind the visitors' gallery.

[18] The long-term trend towards electronic trading platforms reduced the Exchange's attraction to visitors, and although the gallery reopened, it was closed permanently in 1992.

The phrase "Big Bang" was coined to describe measures, including abolition of fixed commission charges and of the distinction between stockjobbers and stockbrokers on the London Stock Exchange, as well as the change from an open outcry to electronic, screen-based trading.

The old Stock Exchange Tower became largely redundant with Big Bang, which deregulated many of the LSE's activities: computerised systems and dealing rooms replaced face-to-face trading.

On 25 April 2019, the final day of the Extinction Rebellion disruption in London, 13 activists glued themselves together in a chain, blocking the entrances of the LSE.

[23] Extinction Rebellion had said its protesters would target the financial industry "and the corrosive impacts of the ... sector on the world we live in" and activists also blocked entrances to HM Treasury and the Goldman Sachs office on Fleet Street.

A wide range of businesses including early-stage, venture capital-backed, as well as more-established companies join AIM seeking access to growth capital.

The AIM is classified as a Multilateral Trading Facility (MTF) under the 2004 MiFID directive, and as such it is a flexible market with a simpler admission process for companies wanting to be publicly listed.

[33] Despite TradElect only being in use for about two years,[34] after suffering multiple periods of extended downtime and unreliability[35][36] the LSE announced in 2009 that it was planning to switch to Linux in 2010.

This merger of Borsa Italiana and MTS with LSE's existing bond-listing business enhanced the range of covered European fixed income markets.

[48] On 12 December 2022, Microsoft bought a nearly 4% stake in London Stock Exchange Group as part of a ten-year cloud deal.

[57] NASDAQ revised its offer (characterized as an "unsolicited" bid, rather than a "hostile takeover attempt") on 12 December 2006, indicating that it would be able to complete the deal with 50% (plus one share) of LSE's stock, rather than the 90% it had been seeking.

[58] On 20 August 2007, NASDAQ announced that it was abandoning its plan to take over the LSE and subsequently look for options to divest its 31% (61.3 million shares) shareholding in the company in light of its failed takeover attempt.

[59] In September 2007, NASDAQ agreed to sell the majority of its shares to Borse Dubai, leaving the United Arab Emirates-based exchange with 28% of the LSE.

[61] Xavier Rolet, CEO of the LSE Group at the time, would have headed the new enlarged company, while TMX Chief Executive Thomas Kloet would have become the new firm president.

Normal trading sessions on the main orderbook (SETS) are from 08:00 to 16:30 local time every day of the week except Saturdays, Sundays and holidays declared by the exchange in advance.