My work is a corpus-based investigation of the use and development of temporal subordinators and clauses in Early Modern British English (EModE).  The focus of the project is on the forms, structure, meanings, and history of these subordinators and clauses. My primary aim is to analyse stability and change in temporal subordinators and clauses across the EModE period; second comes the study of linguistic features, such as aspect, tense, mood and modality, ellipsis and non-finite forms, positions, coordination, and subordination of the temporal clauses. In addition, I examine the progress of these subordinators, and WHEN in particular, across text categories, text types, and the sub-periods. Regarding temporal subordinators, I account for the use of simple, complex, and correlative forms. I also address alternative expressions of temporal subordinators such as the repetition and replacement of temporal subordinators. The influence of negation on the choice of subordinators, and the modification patterns of subordinators are also treated. Primary meanings of anteriority, simultaneity, and posteriority as well as secondary meanings of temporal subordinators are studied. I uncover the evolution of temporal subordinators and trace their various forms, as far back as possible to the Old English and Middle English periods. I also make some comparisons with Present-day English. The investigation is based on the EModE section of the computerized Helsinki Corpus of English Texts and the manual literary Major Authors Corpus which I designed for the purposes of the study. Consequently, my study is carried out within corpus linguistics methodology. All in all, the primary material yielded 3,269 instances of 17 different prototypical temporal subordinators, called sub-types.