Some (slightly relevant) background information: The British Empire historically came into being in 1583 when American expansion began. In 1707, the Kingdoms of England and Scotland merged to form the Kingdom of Great Britain. The American Revolution of 1765-1783 led the British Empire to turn eastward, commencing global expansion and eventually becoming the world's largest empire in recorded history. Following Napoleon's defeat, the Pax Britannica - the British Imperial Century of 1815-1914 - dawned on the British Empire.
The British wizarding community was governed by the Wizards' Council since medieval times until 1707, when it was replaced by the Ministry of Magic, which is considered to be "a more highly structured, organised and complex government structure". The nature of these two governing bodies and the history behind their transitions tell us about the roles the wizarding community played in British history, if any.
Before the British Empire
- The Wizards' Council appeared to emulate a tribal power structure, its leader being given the title of Chief. The loose, informal nature of such a governing body, coupled with the feudal state of the kingdom at the time, meant that the English were unlikely to have access to wizards in an institutionalised and systematic manner, nor anything approaching a military scale.
- The presence of Merlin did imply that the English court had access to wizards at an individual level. Such court wizards were indeed involved in national affairs.
- The existence of martial magic and the title of Warlock today hints at a possible history of the usage of magic in warfare at some point in the distant past, medieval or earlier.
- As the world emerged from the feudal era, the royal courts of Europe began to consolidate power. The Wizards' Council also evolved in reflection of the changing times, becoming more bureaucratic and institutionalised. As an example, a medieval law passed in 1362 to ban Quidditch near Muggle settlements was a simplistic, straightforward one-liner, while the 1631 Code of Wand Use had a legally recognised name, for starters, and was organised into clauses and such modern legal jargon. This suggests that the English government could have access to previously unavailable wizarding resources and powers if it wished to, theoretically.
- However, anti-wizard sentiments started rising alongside the trend of witch hunts since the early 15th century:
"As the witch-hunts grew ever fiercer, wizarding families began to live double lives, using charms of concealment to protect themselves and their families. By the seventeenth century, any witch or wizard who chose to fraternise with Muggles became suspect, even an outcast in his or her own community." - Albus Dumbledore
- Such circumstances meant that wizards were increasingly reluctant to reveal their identities, so their involving in national affairs were expected to decrease, increasingly focused on self-governance alone.
After a final, failed attempt to seek official recognition and protection by the British monarchy, the International Confederation of Wizards finally resorted to passing the International Statute of Wizarding Secrecy, in order to save themselves before the witch hunts escalate into any anti-wizard genocide. It was signed in 1689 and enacted in 1692. In 1707, the Ministry of Magic was established to replace the Wizards' Council, in order to effectively enforce the Statute of Secrecy within the British Empire.
"Upon the signature of the International Statute of Secrecy in 1689, wizards went into hiding for good." - Bathilda Bagshot
With the wizarding world hidden in secrecy from the Muggle world since 1689, there are no intentional wizard involvement in the affairs of the British Empire from that point.