Lee Kun-hee, who transformed Samsung Electronics Co. from a copycat South Korean appliance maker into the world’s biggest producer of smartphones, televisions and memory chips, has died. He was 78.

Lee died on Sunday with his family by his side, the company said in a statement, without mentioning the cause of death. His family will hold a private funeral. He had surgery in 2014 after a heart attack and was treated for lung cancer in the late 1990s.

Lee, who told employees to "change everything except your wife and children” during his drive to foster innovation and challenge rivals such as Sony Corp., was South Korea’s richest person. He had an estimated net worth of $20.7 billion, according to the Bloomberg Billionaires Index. Samsung, the biggest of South Korea’s family-run industrial groups, known as chaebol, has been led by his only son since the heart attack.