Samsung Electronics has announced the death of its chairman, Lee Kun-hee. The company says he died on October 25th with family including his son, vice-chairman Lee Jae-yong, at his side. He was 78.

A cause of death was not given, but Lee had been incapacitated for many years after suffering a heart attack in 2014, causing him to withdraw from public life. Lee Jae-yong, also known as Jay Y. Lee, had been widely assumed to take over upon his father’s passing and has been viewed as the de facto leader in recent years.

Lee Kun-hee was a controversial figure who played a huge part in pushing Samsung from a cheap TV and appliances maker to one of the most powerful technology brands in the world. He became the richest man in South Korea, with the Samsung group contributing around a fifth of the country’s GDP. In its statement, Samsung says that Lee’s declaration of “new management” in 1993 was “the motivating driver of the company’s vision to deliver the best technology to help advance global society.”

Lee also found himself in legal trouble. He was found guilty of bribing President Roh Tae-woo through a slush fund in 1995, and of tax evasion and embezzlement in 2008, but was formally pardoned for each conviction. The second pardon came in 2009 and was made “so that Lee could take back his place at the International Olympic Committee and form a better situation for the 2018 Olympics to take place in Pyongchang,” South Korea’s justice minister said at the time.

Lee’s passing will reignite inevitable speculation over the succession process. While Lee Jae-yong has long been groomed to become chairman, he’s had legal issues of his own since his father’s incapacitation, spending almost a year in jail for his role in the corruption scandal that brought down former South Korean president Park Geun-hye. South Korean law also means that anyone assuming Lee’s assets will face paying several billion dollars in inheritance tax, which may force them to reduce their stake in the company