Autotagging is the process of automatically assigning keywords/tags to images based on the image content without human intervention. The digital asset management system Canto Cumulus has offered the computer vision software Clarifai, trained using artificial neural networks, as a plugin for autotagging since 2021. The image archive of the ETH Library has had its entire image stock of over 1 million images autotagged with Clarifai’s General base model to supplement the hierarchical keyword catalogue. The autotags were then analysed to assess the quality of the AI recognition, creating a large historical database enriched with AI and validated for further applications in the digital humanities and for generating new AI models for historical image material.