Legg Mason investor Bill Miller has led a $4.5 million investment in Personal, the Steve Case-backed startup that serves as an online storage vault for people’s most sensitive information and documents.

Miller invested his own money in the Georgetown company and will be joining Personal’s board of directors, according to an announcement on Tuesday by Personal.

Personal was launched four years ago by co-founder Shane Green, who is the chief executive, and Doug Wheeler, who is Personal’s chief operating officer.

Green said the new money will be used to expand Personal’s business, including the introduction of an automatic, online form-filling tool that helps people fill out forms.

“We will be hiring five people almost immediately,” Green said. “We are growing the company.”

Personal has several prominent investors in addition to Case, including Washington sports mogul Ted Leonsis, Carlyle Group managing director Ed Mathias, former ambassador Morton Abramowitz, Virginia venture capitalist Don Rainey and former AOL chief executive Jonathan Miller. New York-based investment house Allen & Co. also has a stake in the start-up.

Prominent technology investor Esther Dyson has also invested in Personal and has joined its board of directors, along with Jonathan Miller.

“We are not profitable,” Green said. “But we earning revenue. We are starting to grow quickly. Its a very excditing time on the revenue side.”

The latest investment round brings Personal total fundraising to date to approximately $20 million.

Miller has been a long-time leader in mutual fund investing and is perhaps best known for being the only person to beat the S&P 500 for 15 years in a row as head of the Legg Mason Capital Management Value Trust.

But Miller stepped down from the fund in 2011 after it underperformed the S&P 500 for five out of six years. He is currently portfolio manager of the Legg Mason Opportunity Trust.