Meta’s antitrust trial, in which the government contends the company killed competition by buying young rivals, hinges on unknowable alternate versions of Silicon Valley history.

Mark Zuckerberg in federal court Monday was forced to revisit a time when he doubted Facebook would be able to compete in mobile photo-sharing, and decided to buy Instagram — testifying in a trial where the US government is arguing it should unwind that acquisition.

Facebook owner Meta Platforms and the Federal Trade Commission squared off Monday in a trial that could shape the future of antitrust enforcement and force the tech giant to break itself up by selling Instagram and WhatsApp.