Collecting and analysing large amounts of data in the Cloud-to-Edge computing continuum raises novel challenges that traditional centralised orchestration solutions cannot handle efficiently. To overcome the limitations of current centralised application management approaches, this paper presents a fully decentralised application-level orchestrator, based on the notion of self-organised interdependent Swarms. Application microservices are managed in a dynamic Orchestration Space by decentralised Orchestration Agents, governed by distributed intelligence that provides matchmaking between application requirements and resources, and supports the dynamic self-organisation of Swarms. Knowledge and trust, essential for the operation of the Orchestration Space, are managed through blockchain-based trusted solutions and the utilisation of emerging methods such as Self-Sovereign Identities (SSI) and Distributed Identifiers (DID). End-to-end security of the overall system is assured by utilising state-of-the-art cryptographic and privacy-preserving data analytics algorithms. A digital twin, that runs in parallel to the physical system, further improves its behaviour with predictive feedback. The presented concept is going to be implemented in the EU-funded Swarmchestrate project that starts in 2024.