Part III discusses the striking triangular relationship between humanitarianism, interventionism, and colonialism and imperialism in various parts of the world. It asks to what extent the idea of humanitarian intervention solidified in international politics as a colonial and imperial practice. Indeed, Chapter 7 will show how closely the struggle against the slave trade was intertwined with the colonial and imperial penetration of Africa. In West Africa British anti-slavery measures, which for strategic reasons increasingly shifted from seaborne military operations to dry land, led to direct interference in the internal affairs of African principalities. A particularly prominent case was Lagos, which ended up being formally annexed by the United Kingdom. From the middle of the century onwards, the by now tried and tested intervention measures came to serve as an example for the suppression of the slave trade in East Africa, increasingly turning the idea of abolition into a decisive catalyst and trailblazer for European expansionism across the African continent. At two international conferences – first in Berlin (1884–85) and then in Brussels (1889–90) – the ‘civilised’ states signed treaties by which they gave themselves a mandate in international law and thereby an effective carte blanche for direct intervention, in the name of civilisation, in the internal affairs of African realms.