Maurice Lévy, one of the most powerful men in global advertising, has named his rabbi grandfather as his greatest inspiration.

Mr Lévy is chief executive officer of the French Publicis Groupe, one of the three largest advertising companies in the world, with a £5bn revenue last year.

In a video interview for the trade magazine Campaign about inspiration, Mr Lévy said he admired his grandfather, who was a rabbi in southern Spain, for making complicated philosophy easier to understand.

He said his grandfather was fascinating because “he spent his life learning”, describing his grandfather reading the works of Dutch philosopher Baruch Spinoza, whose work was rejected by the rabbis, as an example of his commitment to learning.

He said: “I was extremely inspired by all his thinking. It was always simple ideas, he made the most complex philosophy extremely simple.”

Mr Lévy also spoke about his father’s wartime escape from Spain under the fascist leader, General Franco.

He explained that his father, a left-wing activist, was imprisoned but then escaped to the south of France, only to have to flee again to Morocco as the Nazis drew closer.

“The Nazis were coming down to France, and were coming closer and closer to Perpignan, and the only way to escape was to go to Morocco.

“He couldn’t go back to Spain, he couldn’t go to Algeria because there was [a policy of] numerus clausus [a limitation on entry, used as an antisemitic policy] for professors, and my father was a professor of philosophy,” Mr Lévy said.

As a consequence, he grew up in the small Moroccan town of Oudja, close to the border with Algeria.

The interview was a rare example of the famously private businessman talking about his family.

It was the first in a series called “Talking Inspiration”, which is presented by Marc Nohr, the chief executive of Kitcatt Nohr Digitas, a company owned by Mr Lévy’s Publicis Groupe.

Mr Lévy was in London this week for the inaugural conference, Advertising Week Europe, the first time such an event has been held on this continent after 10 years of such meetings in the US.

Over 250 lecturers will give talks, including Sir Martin Sorrell, founder of rival advertising giant, WPP.

Publicis Groupe employs 54,000 people and has a presence in 109 countries. Agencies it owns include Saatchi and Saatchi, Digitas and Rosetta and its high-profile British clients include the BBC, BP, easyJet and Cadbury.