Wilfried Martens, who led nine Belgian governments and the European Union's Christian Democrat group, has died aged 77.
Party leader Wouter Beke said today that Mr Martens had died overnight. He did not provide details of where and why he died, but heart problems have long affected his health.
Leading members of his party lauded Mr Martens as a tireless leader to keep his nation of Dutch and French speakers together while giving the two linguistic regions ever more autonomy.
Mr Martens led nine governments in the 1980s and early 1990s and proved capable of keeping the volatile factions in the nation together.
He also helped found the European People's Party and led the EU's Christian Democrat group for almost two decades before asking last week to be relieved from the job.