When my wife was young, she lived in a small village in mid Wales. One day, one of her neighbours decided not to shop in the local market town but to travel away to the big city. When she got there, she found a junction that was controlled by traffic lights. She was so freaked out by this bit of modern technology, that she had to be guided through the town by a friendly policeman. True story.
There are many anecdotes about how, until comparatively recently, people didn't travel the way they do today. Laurie Lee's famous novel, Cider with Rosie, describes how, in the middle years of the last century, many people never travelled more than a day's walk from their village. So we have this notion that people's lives used to be very limited geographically.
In fact, around the beginning of the 19th century, when His Majesty's Confidential Agent is set, the world was not nearly such a big place as we think. The Napoleonic Wars were, in their way, world wars. British forces clashed with the French and their allies throughout Europe and the Middle East. The French supported Indians fighting the British in India and Britain invaded South America. In London's National Army Museum there is a map showing the movements of one private soldier during this period. Over the course of just a few years, he travelled halfway round the world.
My story follows the life of a real person, James Burke. He was born in Ireland but went to France to fight under the French flag. The French sent him to Saint-Domingue (now part of Haiti). There, he surrendered to the British and returned to this country. Eventually he was ordered to Buenos Aires. He also travelled to Spain and spent time in Brazil. He will have seen much more of the world than the average man of the mid-20th century.
Colonialism in those days made the world, in many ways, a very small place. It also allowed for adventures on a very grand scale. I hope you enjoy reading about them.