This study investigates the degradation of regenerated-cellulose fibres in relation to textiles to provide insight into how the crystallinity of the fibres impact it’s interaction with environmental drivers. Adopting a dual focus, this work sits across two different spheres of research. Firstly, investigation of the degradation of cellulosic fibres disposed of in the environment is relevant to textile waste management. This work will facilitate our understanding of appropriate waste disposal strategies and determine the relative impact of these different cellulosic fibres on the environment. Secondly, the preservation of cellulosic fibres in the context of heritage through understanding which environmental conditions are most damaging for cellulosic textiles; will help guide long-term preservation strategies offering clarity on the lifetime of these fibres in collections. By understanding how regenerated cellulosic fibres degrade we can both facilitate their preservation and expedite their degradation by understanding the fibres' interactions with various environmental drivers relative to their crystal properties. The primary objectives of this study were to establish how different degrees of crystallinity found in cellulose fibres impact their degradation. In addition, we also explore how the relative crystallinity of cellulose fibres changes as it degrades. Accelerated ageing was conducted on four types of cellulosic fibres with different ratios of crystalline to amorphous regions. These were aged at 80oC and 75% relative humidity for 3 months to induce thermal and hydrolytic degradation. Fibres were monitored for chemical change using FTIR spectroscopy focusing on changes in peaks representative of the glycosidic link to establish a potential breakdown of the polymer backbone. To monitor crystallinity, XRD was used to establish changes in the cellulose’s crystallinity index (CrI) to determine if degradation in the crystalline region is preceded by the amorphous region. These changes were correlated with the physical degradation of the fibres using colourimetry, microscopy and visual observations. This work provides a more complete understanding of how chemical and structural changes manifest physically as the material degrades. These results provide an initial understanding of how the crystallinity of these fibres provokes different interactions with their environments despite having the same fundamental chemical composition.