Job: Former Enron chief executive, chairman and board member
Before resigning at the end of January 2002, he was chairman and chief executive of the failed energy trader.
After the company collapsed, he became the focus of the anger of disaffected employees and pension and stock holders who had lost billions of dollars.
He had, in happier days, been credited with building Enron's staggering success.
He took up the reins at Enron in 1986 after it was formed from the merger of two pipeline firms in Texas and Nebraska.
Over the next decade Enron grew into the world's largest energy trading firm.
But, under his leadership, the company managed to conceal its massive debts through questionable accounting.
He relinquished his chief executive role in December 2000 and was replaced by Jeffrey Skilling. In August 2001, however, he resumed day-to-day management of the company after Mr Skilling resigned.
Mr Lay was a political ally of the Republicans, particularly President George Bush, who once nicknamed him “Kenny boy”.
Enron contributed millions of dollars to various political campaigns and Mr Lay, along with other Enron executives, advised on US energy policies. He was also a prominent figure in Houston arts and charity circles.