The British wanted an empire for a number of reasons. Firstly, the discovery of the New World provided the opportunity to acquire wealth. The Americas were rich in metals and minerals and the English, then British, were eager to capitalise on these. The vast spaces found in the Americas also provided an opportunity for expansion. This could be used to alleviate the pressure on land at home; be farmed for goods required in Britain and provide trading posts on the way, hopefully, to the Far East. Trade was a large motivation. The want of profit led to the formation of companies such as the East India Company and the Royal African Company. These were established to make money, territory was taken to ensure that the profit remained British. As other European nations also colonised there was a sense of needing to expand and protect. A snowballing effect takes place. With each threat to trading routes or British interests, the need to strengthen, often through conquest, became greater. Exploration and sheer inquisitiveness was also a motivation. Again some of this is motivated by trade and making money, some parts are explained by explorers wanting to discover more about the world. As the empire was established there was a growing trend towards missionary work. Some people believed that it was right and proper to try and instil Christian or British values on areas. This in turn led to expansion. Other motives for wanting to expand include the desire to keep undesirables away from mainland Britain. Transportation was used to both the Americas and more famously to Australia.
The British Empire – Making of the United Kingdom – Economic Consequences of the British Empire – How did the Empire affect Great Britain? – Society changes: Political Thought and the British Empire – Questions about the British Empire – British Empire Teaching Resources