At the end of 1818 the first duke of Wellington returned to Britain after making his name and fortune on the continent. Despite primarily being remembered as a military hero and diplomat, his excursion into party politics upon joining Lord Liverpool's cabinet constituted a second career that continued until the duke's death in 1852. This thesis sets out to analyse that political career from 1819 to the first Reform Act in 1832 through Wellington's unsolicited correspondence. This previously neglected source offers a revealing insight into the popular perception of politics, society and Wellington himself, which often challenges the assumptions made about press and public opinion. Indeed, these letters themselves can be regarded as a form of public opinion. Hundreds of ordinary people from across the country wrote Wellington on every matter of government and society, for personal, commercial, political or charitable reasons. They wanted patronage for themselves or friends, money and favours. They contributed to debates on Catholic Emancipation, Parliamentary Reform and Economic distress. A sizeable minority wrote anonymous, threatening letters in an attempt to intimidate Wellington, while others gave the duke their wholehearted support. These letters reveal the politicisation of 'The People' and their willingness to get involved in public debates. The correspondents often used the same language and terms of reference. They wrote with the same concerns, albeit for different reasons and with varying suggestions. These letters also provide a glimpse of the popular perception of Wellington - how this military hero was considered, in turn, to be a saviour, influential friend and 'evil nemesis' of the people. Wellington did not ignore this correspondence. Most people got a reply. Their letters were filed, discussed, forwarded to appropriate people, acted upon and investigated. Crucially, some of this correspondence influenced the duke's thinking and impacted on events. Writing a letter to a member of the ruling elite could make a difference.