Previous studies about democracies on a global level have assumed that democratisation occurs when an autocratic regime moves toward becoming a democratic regime. This article recognises an alternative mode to democratic transition: democratisation by state-formation, which occurs when democratic regimes are established in new states as an outcome of state-formation. The article describes how cases of democratisation can be classified according the two modes of democratisation. Furthermore, the classification is applied in illustrative analyses of democratisation on the global level during 1800-2007. The analyses describe how transition and state-formation have affected the global number of democracies. These analyses indicate that both modes of democratisation have empirical relevance and that the classification provides a more complete description of the global development of democracies than previous studies. The main conclusion of this article is therefore a proposal for future studies to include both modes to understand and explain democratisation on the global level.