With the inception of European colonialism during the Renaissance, European languages started to spread around the globe. The prime agents were Portuguese, Spanish, English, and French, with Dutch, German, Russian, Italian, and Danish playing a less important role. As a result of their colonial histories and twentieth-century developments, English and Spanish have become the two most widely spoken post-colonial languages world-wide today. Taken together, recent calculations estimate that they have slightly over 820 million native speakers across the globe (with English contributing around 378 million and Spanish about 442 million). Moreover, the two languages share aspects of their colonial and post-colonial development while, at the same time, showing striking differences in the sociolinguistic and typological developments of their respective offspring varieties. Surprisingly, however, a systematic comparative account of the rise of English and Spanish to their current roles as world languages has not been attempted so far. It is one of the aims of the present volume to fill this gap.