The English version of the heavy tome, "Capital in the Twenty-First Century", is the bestseller on Amazon in the United States and has sparked a political debate about the widening gap between rich and poor.
Critics have tried to deride his work by labelling him a neo-Marxist, but it gained him an audience at the White House earlier this month with top economic advisers to President Barack Obama.
Similar debate has been ignited this week in Britain, where the book officially goes on sale , although it is already selling well.
Harvard University Press says an estimated 200,000 copies have been sold across both the US and Britain this year -- a startling success for a 700-page book about economics.
"What people like is this is a readable account of issues that people care a lot about," Piketty told AFP after a sold-out event launching the book in London, organised by the IPPR centre-left think tank.
"There's always been concern about inequality, but what's new in the book is that I put a lot of historical data together. Until recently there was relatively little evidence.
"Here, at least people know what they're fighting about -- this is not going to put an end to the political fight about inequality, but maybe we will have a more informed fight."
Piketty uses data from the past two centuries across 20 countries to demonstrate how inherited wealth has ensured the dominance of a small class of people and will continue to do so unless action is taken.
He rejects the widely-held argument that economic growth in the capitalist system benefits everyone, and advocates a punitive global tax on wealth to address the problem.
Among the 250-strong guests at the London event was an advisor to British opposition Labour leader Ed Miliband, who said in a speech in February that "tackling inequality is the new centre ground of politics".