This thesis covers a wide range of topics from historical to computational and corpus linguistics as well as synchronic and diachronic syntax and information structure. The latest insights in each of these sub-fields of linguistics are necessary to address what has been a vexed problem in the study of Middle Welsh for a long time. Middle Welsh word order is particularly puzzling, because there is a wide range of verb-second patterns and the distribution of those is not at all clear. Secondly, these so-called 'Abnormal Orders' are only found in the Middle Welsh period; Old and Modern Welsh mainly exhibit verb-initial patterns. Verb-second orders are shown to have developed from earlier patterns with hanging topics and focussed cleft constructions by carefully reconstructing their syntactic history in Old Welsh and related Celtic languages. A detailed analysis of a syntactically and pragmatically annotated corpus, built especially for this thesis, reveals that a combination of these features explains which word-order pattern appears in which particular context. From a diachronic syntactic point of view, Middle Welsh shares some crucial developments in the rise of V2 with Early Romance, but it differs in others.