The Grand Lodge of the British Isles is a Masonic Grand Lodge which governs Masonic lodges in the British Isles, as well as in many of its former colonies, and this is done chiefly through intermediary Provincial Grand Lodges.
Freemasonry in the British Isles has its origins, ultimately, in the medieval era. As with other occupations in the era, stone masons, or as they tended to be known in the era, freemasons, were organized into guilds, but unlike other occupations their only employers were the Crown and the Church. This meant they migrated in groups for new work and stayed at groups of tents they called "lodges". Due to them only having a few employers, stone mason guilds tended to be far simpler in organization than other guilds, and they tended to be as a result more egalitarian. Furthermore, due to their associations with organs of a state, they tended to view themselves as exceptional relative to the rest of society. The secret handshakes and rituals that they invented like other guilds were quickly centred around alleged grand pasts connecting them to King Solomon.
While in England the stone mason guilds fell into decline due to the end of the monasteries, in Scotland they instead received state patronage and regulation over the sixteenth and seventeenth centuries. Furthermore, gentlemen and other non-masons began to join masonic lodges, and by the eighteenth century they overshadowed actual masons within these lodges. These Masonic Lodges creeped down the border, and in 1717 they formed a Grand Lodge in England. The next few years saw Anderson publish his Constitutions, which standardized Freemasonry and, more notably, allowed any monotheist of any stripe to become a Mason. The next few decades, where Irish Masons migrated to England and organized their own lodges without the consent of the Grand Lodge of England, resulted in their emergence as "Ancients", a Masonic movement unrecognized but with a stronger populist streak. The existing English Masonic order they called "Moderns", and they believed in restoring a more "pure" Freemasonry. Both forms spread across the empire, and even beyond. As Freemasonry erupted across Continental Europe, it attracted subversive radicals and was condemned as an anti-church by the Catholic Church, and this has given it its modern reputation; in contrast, in the British Isles and the Empire, it was heavily establishment and sought aristocratic and royal patronage, and its leadership was chiefly Anglican as a result.
Over time, Modern and Ancient Freemasonry in the British Isles were effectively brought under the same hands of royal patronage. In 1813, they were finally unified, with the Duke of Kent as the Grand Master of the United Grand Lodge of England. The Duke of Kent was the brother of George IV and his brother Frederick. Consequently, when in 1827 a mob stormed the Tower of London, King Frederick fled along with many of his aides, and a Constituent Assembly was convened, Freemasonry lost much of its elite. The Grand Lodges of England, Scotland, and Ireland effectively collapsed, and each Masonic Lodge was effectively separate from one another. In the extremely chaotic atmosphere of the early revolutionary state, this resulted in an immediate danger. It is known that many lodges signed on to the Orange Order and became Orange Lodges, and many of them participated in violence in this era. Some ex-Masons even participated in the Burning of Parliament, although when the backlash against it caused the destruction of the Orange Order some of them signed on to the Scarlet Order's mission of establishing a very powerful monarchy under a broad electorate. In general, the secret nature of these lodges resulted in much state anxiety, even from those who were Freemasons themselves. This came particularly from Radicals, who ironically viewed the Freemasons as a body of counter-revolution. As a result, over the 1830s, they made efforts to stitch together Masonic lodges into a network, and in 1838 they finally unified their provincial networks into a single Grand Lodge of the British Isles. This new Grand Lodge left out many lodges, and in particular it left out the ones who felt allegiance to the Hanoverians over the Water. But, for the most part, the great confusion of British Freemasonry came to an end.
The Grand Lodge quickly sought to spread across the empire. With many lodges in British North America dead, loyal to Hanoverians, or effectively American in nature, it established many new ones with new Provincial Grand Lodges in capitals of colonies. In particular, in Lower Canada, the new Freemasonry became quickly dominated by Francophone anticlericals who defied Catholicism's opposition to it, in contrast to the pre-revolutionary form which was mostly Anglophone and Protestant. In India, the need to stitch together alliances after the costly Anglo-Burmese War as well as the continued ghazi attacks in reaction to missionary activities resulted in Freemasonry being viewed as a way to create bonds between Indians and the Raj. While Freemasons in the Raj were already admitting Muslims and Parsis, they stopped short of admitting Hinduism due to its polytheism and the issue of caste. With the era seeing the rise of Hindus who brought its monotheism to the surface and regarded caste as a social rather than religious practice, the new lodges admitted Hindus. And thus was the birth of Freemasonry as an ideology of empire.
During the Anglo-Spanish War of the 1840s and -50s, Freemasonry played a role in funding the war effort, and soldiers took it with them as far afield as the Philippines. And with the disestablishment of the churches in 1853, the closeness of Freemasonry with power, among both the Radical and Moderate parties, led many to nickname it the new national church. At the same time, the Grand Lodge of the British Isles zealously guarded its role as the chief lodge of the empire, refusing to allow for the formation of any other Grand Lodges at the same level (though splinter lodges emerged anyways). As the British Empire continued to expand, new lodges popped up wherever they went, and they made moves to include "natives" as part of them though they could not generally proceed beyond the second level. Some dreamed of making Freemasonry the bedrock of a new universal religion, and as certain Masonic rituals slowly became a part of British civil practice, they believed those days were coming. But ultimately they did not, as many did not take Masonic ritualism seriously, and the inherent white supremacist nature of British Freemasonry made this impossible. But yet, its reach was impressive, and it did bring together classes of the Empire like few institutions did. When some advocated the unification of the colonies with the British Isles in an American-style union, Freemasonry strongly supported it, but nevertheless ultimately such attempts were unsuccessful.
With the rise of women's rights movements, Freemasonry's restriction on female membership saw scorn; though in France some level of female membership was always accepted, the same was not true in the British Isles. Some mixed-gender lodges saw their establishment, and though there was some discussion on including them into the imperial Masonic network, ultimately this did not come to be. And indeed, when the Grand Orient of France made moves on including more women, the British reaction was to declare the French irregular. Similarly, attempts to include atheists were refused.
With the emergence of liberal movements in the nonwhite colonies, ironically Masons played a role in this. They attempted to leverage their Masonic connections for liberalism, and when their white brethren refused any discussion of this as "political", they decided to form their own independent lodges. Such lodges popped up in India, Natal, and West Africa with alarming alacrity, though most got suppressed. And at the same time, an anti-Masonic impulse rapidly formed, as its association with the colonial state made it hated. Such sentiments erupted in 1937, with the Hindustani War of Independence; though led by many members of independent lodges, the leading anti-Masonic attitudes led them to hastily burn their robes and join in calling for the death of Freemasonry. Ultimately, the Hindustani rebels proved victorious, and a great mob destroyed the Provincial Grand Lodge of Allahabad in celebration. The Hindustani constitution continues to contain very strong provisions banning secret societies as a result of this.
Elsewhere, decolonization saw Freemasonry indigenized and separated entirely from British tradition. But nevertheless, the lustre of imperial Freemasonry was gone. And with it came backlash at home. The Associationists were long critical of it as a middle class-led movement, even though some of them were members of it, but they were now part of a wave that aimed at "separation of lodge and state". This wave did successfully weaken Freemasonry's role in the state, although this wave ultimately swallowed itself as this force attracted conspiracy theorists who discredited the whole movement. And it forced Masons to allow tours of their lodges and support much charitable work, as part of showing themselves as being a social club. But nevertheless, much formerly-Masonic ritual remains part of civil practice, and it is very easy to find Masonic symbols across buildings in the British Isles.