Every morning in his townhouse in the tony San Francisco neighborhood of Pacific Heights, the man once referred to as Britain’s Bill Gates gets to work.

That man, Mike Lynch, checks in with his investment firm, Invoke Capital, on its recent performance. He speaks with researchers in Cambridge, England, whom he funds personally, about the ways artificial intelligence could be used to help those with hearing difficulties. He receives updates on the heritage Red Poll cattle and other livestock at his farm in Suffolk, in the east of England.

Eventually, Mr. Lynch, 58, turns to his most important task: defending himself against 16 criminal counts of conspiracy and fraud. If convicted, he will face up to 20 years behind bars.

The trial begins on Monday in San Francisco, where federal prosecutors — who extradited Mr. Lynch from Britain in May and placed him under house arrest — have accused the former tech mogul of defrauding Hewlett-Packard of billions when he sold HP his software company, Autonomy, for $11 billion in 2011.

In 2012, HP announced an $8.8 billion write-down and blamed it on “serious accounting improprieties” at Autonomy. Stunned investors called it one of the worst acquisitions in history. Mr. Lynch has since waged a series of complex, overlapping legal battles in the United States and Britain.

In 2022, a London judge in a civil case found Mr. Lynch and Sushovan Hussain, Autonomy’s former finance chief, liable for defrauding HP The judge said the case was “amongst the longest and most complex in English legal history,” with the trial running for more than three months, the presentation of tens of thousands of documents and, in the end, a ruling that ran to well over 1,000 pages.