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Work here

The Agency
7 Place de l'Europe
14200 Hérouville Saint-Clair



The Dôme
Esplanade Stéphane Hessel
14000 Caen


Here as well

Paris team
Commercial Manager
Technical Manager


Casus Belli
A marketing consultancy agency at the service of communication that, with its planners and creatives, assists companies and institutions in a changing world.

Casus Belli
An agency that reinvents the model through the exploration of social and technological innovations, in order to legitimize the actions by offering experience centered on users.


The Web


The new media


Users' experience


The model through exploration


The Changer d’angle

the manifesto

Team Team




    Jerome is an enthusiast who spent some time between the world of video games and startups before creating, with Matthieu Forget, Casus Belli; A name that is a tribute to their first love, role playing.
    Jerome, with his pioneering spirit, manages the project teams and conceptualizes inordinate operations. A finder of improbable phrases, he phones while walking (or walks while phoning) and is also a serious cook.
  • Matthieu FORGET

    Matthieu FORGET


    Matthieu could have chosen accountancy but curiously he preferred the internet when it was still in its infancy. After having created his first major business at a time when it was still referred to as a web agency, he teamed up with Jérôme to create Casus Belli. His pragmatic mind is always on alert; passionate about Strategy and a History buff, no one dares challenge business plans, profitability ratios or any subject in the form of an Excel table.
  • Corinne MARCEAU

    Corinne MARCEAU


    Corinne is pure Parisian, 100% communications agency with the names made from the initials of the founders. Corinne met Jerome and Matthieu for a single project site redesign; their freedom for innovation, research excellence, their creative sensibility, and she was seduced. After several years of traveling back and forth to Caen, Corinne has chosen to live in Normandy to think of new uses, create brand platforms and conceive communication strategies (and travel back and forth to Paris more often..).
  • Matthieu LE SOLLIEC

    Matthieu LE SOLLIEC


    Matthieu is an explorer, he lived in Liverpool to obtain a Masters in Digital Art, studied synesthesia, moved to Paris to work as AD on prestigious accounts of large agencies: Peugeot, Boucheron, Mappy, Leroy Merlin. In 2012, he pushed open the door of the agency where he can be free, sassy and an outside of the box creative realist.
  • Gaël RAYON

    Gaël RAYON


    Gaël is a graphic designer and self-taught motion designer. It all started in the golden age of handmade internet when portals like and yahoo triumphed! An avid art, technology, animation, video games and science lover, after a traditional AD career, he created Brother System, a laboratory of creative technology. Gaël joined the agency after several years of collaboration to create the Event-Installation offer and is one of the key actors of the Laboratory.
  • Sébastien FINOT

    Sébastien FINOT


    Sebastien is passionate about computers in all forms but especially video games ... (him too). Self-taught, an explorer, he has worn different hats, from developer to project manager and moved in the worlds of cinema, communication, fashion, Parisian agencies (him too). After having experienced journalism, one of his childhood dreams, he returned to the root of his passion : computing. In 2012, an interview and he becomes Technical Director at the agency where he is THE expert, provides R & D and is the best provider of pragmatic solutions.
  • Yann RAYON

    Yann RAYON


    Yann is the developer! And it is not just a job. From the age of 7, he loved programing Oric and Amstrad. The code lines are like a music score for Yann who is a musician, photographer and is passionate about Japanese animation and video games. The days are always too short to satisfy his creativity, especially since he has taken the time to create Brother System with his brother. Like him, he joined Casus Belli and is involved in the Laboratory and the Event-Installation offer as well as the many projects of the agency.
  • Morgane NEELZ

    Morgane NEELZ

    Project manager

    As her cat, Morgane has lived several lives, with a diploma from CELSA in her pocket, she travelled the world as a « comm-trotter ».
    Her life at Casus Belli drives her as fast as her motorbike: it’s always with a smile that she steers between client support, reflection, coordination and project management.
  • Charlotte HUREL

    Charlotte HUREL

    Project manager

    It is a musical encounter and since summer 2017 Charlotte gives rhythm to the agency project management. She manages, coordinates long term projects in communications, marketing or exploration.
  • Maxime CHARON

    Maxime CHARON


    Maxime is the man of words. After living as a Parisian for a few years, he returned to his native Normandy, picked up his schoolbag, this time as a Professor and to design concepts for the agency and create his own Brand and Social Content agency inside AsUWish group.
  • Quentin DUVAL

    Quentin DUVAL


    Quentin wears many caps and always with panache. Project manager, web developer and integrator, multimedia developer, the master of XHTML, HTML5, CSS3, SASS, responsive & adaptive. Quentin with his computer degree, Software and Multimedia Developer joined the agency in 2013, to challenge the limits of platforms and make them retreat, such as Drupal, Joomla. Of course, video games are part of his world !
  • Geoffroy RIOU

    Geoffroy RIOU


    After a Master 2 and several years in Brittany (or almost), Geoffroy pushed open the doors of the agency in September 2015 and was immediately welcomed by the geeks and gamers of the agency. Geoffroy is the big hearted geek capable of laughing at children's jokes and bending himself backwards to meet the demands of his project managers.