Top Management Team

Olivier Darrason

Founder & Chairman of the Advisory Board

Olivier Darrason attended the Institut d’Études Politiques (IEP) in Aix-en-Provence and the École Nationale d’Administration (ENA) (Aguesseau class). He started out as sub-prefect in Guadeloupe (1982) and Var (1983-1986), then became Chief of Staff of the French Ministry of Culture and Communication (1986-1988), and then Secretary-General of SVP, a management consulting company (1990-1993). He was elected MP for Bouches-du-Rhône (Istres/Fos/Martigues/Saint-Mitre/Port-de-Bouc) from 1993 to 1997. He founded CEIS in 1997. He particularly specialises in defence matters and has participated in various major reforms.

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Guillaume Tissier


Guillaume Tissier holds a graduate diploma (DESS) in international business law. He started out as a journalist specialising in economic and legal affairs, then worked as a consultant at DATOPS. In 1997, he joined CEIS’s Risk and Crisis Management department. There, he was particularly involved in consulting assignments in information security and cyber risk analysis. He was appointed CEIS’s Managing Director in 2012 before becoming chairman in December 2018.

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Axel Dyèvre

Associate Director

Axel Dyèvre manages CEIS’s Defence and Security industry activities. He is also in charge of CEIS’s European Office, which he created in 2006. Axel started his career as an officer. He was a strategy consultant from 1995 to 1997, then a Senior Partner at DATOPS (now LexisNexis Business Information Solutions), a company developing information systems, from 1997 to 2005. At DATOPS, Axel designed, rolled out and implemented monitoring and intelligence solutions for government agencies and large companies. Having participated in the CEIS adventure since its origins in 1997, he joined the company’s operations in 2006 to open the European Office in Brussels. Axel holds an advanced degree in business administration from the École Supérieure de Commerce de Paris (ESCP).

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Vincent Riou

Associate Director

After 11 years of experience in project management at the Directorate General of Armaments (DGA), where he was in charge of electronic war and intelligence programmes, Vincent Riou joined the Steria group. There, he supervised the Defence and Security department for 5 years. Vincent has been at CEIS since 2012 and was in charge of directing the company’s business development before taking over the cybersecurity unit in 2017. He holds a diploma in engineering from the École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne) and a master’s degree in business administration from the Institut d’Administration des Entreprises (IAE). He is also an auditor of the 47th national session of the French Institute of Higher National Defence Studies (IHEDN).

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Didier Castres

Senior Strategic Advisor

After a classical career beginning alternating command time in army units and staff positions, General Castres then occupied a succession of politico-military positions: military Staff at the President’s cabinet, Head of the joint Operations Center (CPCO) at joint staff, Deputy Chief of Staff for Operations at joint staff, and General Inspectorate of the Armed Forces.
In 2018 he joined CEIS as Senior Strategic Advisor. He advises States on their defense and national security strategy, helps the development and optimization of army models (organization, capacities, decision-making processes, training) and performs various types of audits in the field of security (including in immaterial fields) and defense for public and private actors.

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Jean-Jacques Brun

Director of Risk Management

Jean-Jacques Brun joined CEIS in 1999. He was in charge of the media desk and intelligence assignments. Today he directs Risk Management activity. He holds a graduate diploma in defence, geostrategy and industrial dynamics from Université Panthéon-Assas and a master’s degree in political science from Université Paris-Sorbonne.

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Chris Brenot

Director of Human Resources and Quality

Chris Brenot, CEIS’s HRD, holds a graduate diploma (DESS) in international industrial and commercial strategies. She started her career as a parliamentary attaché, then joined CEIS as a consultant in political and parliamentary monitoring. She is also head of quality at CEIS, which has been ISO 9001-certified since 2002.

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Bruno Denoyelle

Director of Public Affairs

After completing doctoral studies in public law and political science, Bruno Denoyelle joined Image & Stratégie Europe, a consulting firm presided over by Thierry Saussez, in 1999. As Associate Director of I&S, he advised managers in the business world as well as elected officials and members of the French government and foreign governments in their public and institutional communication and during national and international electoral campaigns. In 2007, he became the first advisor to the Interministerial Delegate for Communication. From 2011 to 2012, he was a consultant in digital and European matters (French Government Information Service [SIG] Matignon).

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Pauline Massart

Deputy head of the European office

Pauline Massart joined CEIS’ Brussels office in June 2018, bringing the company an experience of 10+ years in European affairs and a large network of institutional and private-sector contacts. She was previously Head of Media & Communication at the European Defence Agency, after heading the Security & Defence Programme of the Brussels-based think-tank Friends of Europe (previously the “Security & Defence Agenda”) for eight years. She began her career at Thales in Italy, after studying at King’s College London, the Sorbonne Nouvelle in Paris and Leiden University in the Netherlands. Pauline is Vice President of the Brussels chapter of Women in International Security (WIIS) and is Treasurer of The Brussels Binder, the online female expert database. She speaks English, French, German and Italian.

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Annie Morais

Financial officer

With over 20 years of experience in accounting and management of both SMEs and large corporations (ESI GROUP, KYOCERA SA, K.B.SA, AMWAY France, Groupe Printemps), Annie MORAIS joined CEIS in October 2003 as an Administrative and Financial Manager. She holds a 2-year advanced technician degree in Accounting & Management.

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Bertrand Slaski

Defence & Security Deputy Director

Managing the Defence & Security activity from the Strategic Sectors B.U., Bertrand operated for over 15 years in both public and private corporations development. His customers’ main stakes include threat evaluation, opportunities’ insight and anticipation.
Bertrand holds a degree in Information & Security (UPEM), and an International relations (Rhodes University).

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