This paper is a corpus-based study of complex prepositions and their development over the last three centuries. After a general description of the distribution of complex prepositions in fiction and non-fiction, the paper focuses on the question of how complex prepositions become fixed as indivisible units. For this purpose, one of the variable phenomena commonly found during incipient stages of the grammaticalization of complex prepositions is discussed in more detail: adjectival premodification of the nominal element (e.g. inhotpursuit of). The results show that a proportionally higher number of such instances coincide with the introduction of the corresponding complex prepositions into the language. In the second part of the paper, the development of three individual complex prepositions (in front of, in (the) face of, and on the part of) is traced both in terms of their frequency and distribution as well as in terms of the changes in meaning that can be observed.