South Korean fabless AI semiconductor startup Rebellions is partnering with UK-based heterogeneous AI computing company Callosum to enter Europe’s sovereign AI infrastructure market. The companies plan to supply more than 100 racks powered by neural processing units (NPUs), specialized chips for AI workloads, to a UK government-backed AI research cluster. The initial deployment could be followed by two or three additional supply phases. Rebellions and Callosum are also co-designing a reference architecture that integrates Rebellions’ NPUs into Callosum’s software platform, allowing customers to use the chips without separate software optimization. Callosum’s heterogeneous computing approach combines different AI accelerators and automatically assigns workloads to suitable hardware, aiming to reduce cost and power consumption without relying on one chip maker. Founded by University of Cambridge alumni CEO Danyal Akarca and CTO Jascha Achterberg, Callosum was the first equity investment recipient of the UK government’s Sovereign AI Fund and recently raised a $100 million seed round, approximately 140 billion won. The partnership is intended to expand from the UK and Europe into sovereign AI markets elsewhere and could test demand for inference-specialized NPUs as an alternative to Nvidia’s dominant GPUs.