Jack Welch, the former chairman and CEO of General Electric, died at 84, according to a Monday announcement from his wife.

Why it matters: During Welch's 20 years at the helm of the conglomerate, the company's market value grew from $12 billion to $410 billion, becoming one of the world’s most valuable companies, CNBC reports. He was known for his streamlining of GE's workforce, cutting its employees by more than 100,000 at the start of his tenure to improve the company's bottom line.