Jan Terlouw, former leader of the D66 liberal party and deputy prime minister in the early 1980s, has died at the age of 93, his family confirmed on Friday. He passed away peacefully at home in Twello during the night, surrounded by relatives, his daughter Sanne Terlouw said.

Terlouw led D66 from 1974 to 1982, giving the party a new identity as a centre-left liberal movement and branding it a “reasonable alternative” amid the polarised politics of the time.

Under his leadership, D66 grew steadily in parliament, rising from six to 17 seats between 1977 and 1981. He went on to serve as deputy minister and economic affairs minister in the short-lived second cabinet headed by Dries van Agt.

Before entering politics, Terlouw trained as a physicist and worked on nuclear fusion research. He entered parliament in 1971, championing environmental causes and successfully opposing the full closure of the Oosterschelde estuary.

After stepping down from national politics, he served as king’s commissioner in Gelderland and was a member of the senate.

Terlouw was also a successful writer of children’s books, including Koning van Katoren and Oorlogswinter, based on his own experiences during World War II. Both books were adapted into films and remain among the best-selling Dutch children’s titles.

He continued to speak in public well into old age, and a 2016 appearance on television programme De Wereld Draait Door — in which he urged people to trust one another again — caused a stir at the time.

In a statement, D66 said Terlouw was “a figurehead and a beacon in a turbulent political world” and praised his mentorship and campaigning spirit.

“The party he loved so dearly will carry his legacy with pride,” it said. His daughter Sanne added: “He was a special father and partner. We hope his ideas will continue to resonate in society.”