The historical development and the linguistic triggering environments for Oberfeld formation in German subordinate clauses represent long-standing research questions in Germanic Linguistics, dating at least as far back as Jacob Grimm's famous Deutsche Grammatik. The present corpus study traces this historical development back to the 17th century. The study is based on three text corpora. For contemporary German, two syntactically annotated newspaper corpora were consulted: the TüBa-D/Z and TüPP-D/Z treebanks,1 which provide linguistic annotations for articles published in the daily newspaper die tageszeitung (taz). For diachronic data, the corpus collection Deutsches Textarchiv (DTA)2 was utilized. The DTA contains texts ranging from 1610 to 1900. All three corpus collections are part of the Common Language Resources and Technology Infrastructure (CLARIN) initiative3 and will be developed further as part of the CLARIN research infrastructure. The study demonstrates the added value that annotated corpora can provide for in-depth studies in historical syntax. At the same time it showcases the added value of interoperable language resources for linguistic investigations that require access to and analysis of multiple linguistic resources.