Fifth EUDIS Defence Hackathon, run by the European Commission (DG DEFIS) under the EU Defence Innovation Scheme. Theme: Autonomy on the Battlefield. Challenge 1: GNSS-denied navigation. Challenge 2: swarm coordination, a multi-agent drone or robot swarm completing a mission with minimal human control. Challenge 3: defined by each local organiser. Open to startups, SMEs, engineering teams, researchers and technology professionals from eligible countries; Ukrainian participants are explicitly encouraged as competitors, mentors or jury members. Participant registration opened 31 August 2026; no closing date is stated on the organiser site. Norwegian host: Kjeller Innovasjon AS.