Sebastian serves as a confidential adviser and strategic partner to select decision-makers. Clients trust him with highly sensitive matters and complex institutional transitions, valuing his discretion, independence of thought, and lateral perspective. His judgement is informed by a career spanning British public life, diplomacy, and the media.

He is the co-founder and chief executive of Open Media, a company he has led for close to four decades. The defining series of this era, After Dark, remains a benchmark for rigorous, uncensored public debate and complex crisis navigation. It ran for close to a hundred editions and was once described in the national press as the most intelligent, thought-provoking programme British television ever produced. Sebastian led After Dark and pioneered formats with world leaders, business tycoons, top scientists and others, cultivating in-depth understanding of persuasion and conflict.

In international policy, Sebastian served for fifteen years as special adviser to four successive directors-general at the International Institute for Applied Systems Analysis in Vienna (IIASA). In this capacity, he navigated delicate governmental relations and institutional strategy across the Atlantic, the Middle East, and Asia, securing consensus in complex, cross-border environments.

He has maintained an association with the University of Oxford for two decades, holding visiting fellowships and senior memberships at St Antony’s College, the Rothermere American Institute, and the Environmental Change Institute. He is currently a visiting researcher at the University of Westminster. Sebastian is fluent in English and German.