Michele Ferrero, Italy's richest man and the owner of a global chocolate and confectionery empire, died on Saturday aged 89, the company said.
His death opens the question of succession and potential tie-ups at the family-controlled Ferrero group, which has sales of around 8 billion euros ($9 billion) and continued to grow through Italy's longest recession since World War Two.
Ferrero dreamt up the chocolate-hazelnut Nutella spread, Ferrero Rocher pralines, Kinder eggs and Tic Tac sweets, turning a provincial chocolate factory into what is widely seen as Italy's most valuable privately-owned company.
The billionaire died at home in Monaco after months of illness, the group said in a statement.
Italian President Sergio Mattarella said he was deeply touched by Ferrero's death, calling him a "born entrepreneur".
Twitter was flooded with messages from people who thanked Ferrero for "sweetening up" their lives.
Ferrero's son Giovanni became chief executive of the chocolate empire after his older brother Pietro, the chosen heir, died of a heart attack in 2011 while cycling in South Africa.
In late 2013, Giovanni denied suggestions that the company had been approached by the Swiss-based multinational Nestle, saying Ferrero was not for sale. But industry insiders say he is less interested than his brother was in running the company.
Ferrero senior was a man of few words who shunned publicity, turning a local business from the Piedmont region into a global giant. He had a reputation as a forceful leader, but also as one who maintained generous working conditions and gave back to his community.
Until a few years ago, Ferrero commuted by helicopter every day from his Monte Carlo villa to company headquarters in Alba, northwest Italy, to taste and help design new products.
He never let outsiders buy into the company, which his father set up in 1946. The group, which toyed with the idea of making a bid for its British rival Cadbury a few years ago, is present in 53 countries.
Forbes magazine described Ferrero as "the richest candyman on the planet", putting him and his family in 30th place on their list of the world's wealthiest people, with a net worth of $23.4 billion.
($1 = 0.8785 euros)
(Additional reporting by Isla Binnie and Elisa Anzolin; Editing by Stephen Powell and Kevin Liffey)