The Aegis name has been around for 22 years but the company’s roots stretch back to the formation of advertising agency WCRS in 1979 and arguably longer.
Carat, now the group’s number one media network, was established in France in 1968.
It did not launch in the UK until 1991, two years after the WCRS Group bought its French parent company, Societe Gilbert Gross Michel Doliner.
By the time of Carat's UK launch the WCRS Group had changed its name to Aegis.
In 1992 Aegis parted company with chief executive and chairman Peter Scott (the S in WCRS) and sold its remaining interest in full service advertising.
In 1994 it moved its headquarters from Paris to London and went on to land its first pan-European accounts in the form of Philips and Disney in 1995.
In 1996 it rebranded its outdoor specialist company Harrison Salinson as Posterscope and made a move into the US.
The same year acquired media agency BBJ, which was rebranded as Vizeum in 2003.
One of BBJ’s founders is the man who become Aegis group chief executive in 2010 and is leading the company into its £3.16bn sale to Japan's Dentsu.
Amid the excitement over the megadeal, we asked Jerry Buhlmann for his thoughts on the journey the company has made.
"Pioneering" was the word he returned to again and again.
"Aegis has been very pioneering in the way it's developed, including in digital. Aegis was one of the first agency groups to move into digital," he said. "Moving into media specialists was pioneering and our move into digital was pioneering."
Carat was the first UK agency to launch a digital team, in 1996, the same year that Aegis acquired BBJ.
At the turn of the century Aegis entered China and also launched a market research division, later named Synovate, which Buhlmann shed last year for £525m in a major change of direction.
Buhlmann said: "Having got into market research in 1999, to come out 12 years later, we continue to invest in media and digital. We have a much higher proportion of revenue from digital than the other groups.
"Since 2005 we have made 85 acquisitions, clearly that has been about the company pioneering and growing. We have a strong cadre of entrepreneurs that bought into the pioneering vision."
Many of those acquisitions have helped build up digital networks Isobar, which was launched in 2004, and iProspect, which was started from a US search agency acquisition the same year.
Buhlmann concluded: "We're the only holding company with a vision for the group that all our networks hold to, and I'm sure that will continue following the deal with Dentsu."