This thesis investigates the changes in whether compound nouns were closed (written as one word), open (written as separate words) or hyphenated in Early New High German between 1550 and 1710. Due to the fact that there were no orthographic norms in the German of this time, graphematic phenomena in this period of the German language are very fruitful to examine. The study is based on a corpus of 249 sermons in 90 different postils. Since this thesis aims to show a diachronic development, the corpus texts originate from six time windows centred around the years 1550, 1570, 1600, 1620, 1660 and 1710. The results of the study show a general development from 1550, when around 80% of the occurrences of compound nouns were written as one word, to 1620, when this way of writing dominated almost entirely. In the texts from the last two time windows, the hyphenation spreads, and by 1710, nearly two thirds of the instances of compound nouns were written with a hyphen. The present study also shows that the geographical origin of a text is of lesser importance for the writing of compound nouns as one word, separate words or with a hyphen. However, the distinction between genuine compound nouns (a compound noun with the modifier in an unmarked case) and artificial ones (a compound noun with the modifier in an oblique case) seems to be of greater relevance. The artificial compound nouns are closed to a lesser extent in the period between 1550 and 1620 and hyphenated to a higher extent from 1660 onwards than the genuine compound nouns. In a second part of the study, the compound nouns of the different time windows are examined from a lexical point of view, showing that many compound noun lexemes were almost consistently written in the same way (either as one word, as separate words, or with a hyphen) in all occurrences within each time window.