https://thenextweb.com/syndication/2019/12/27/5-milestones-that-shaped-50-years-of-internet-history/

Fifty years ago, a UCLA computer science professor and his student sent the first message over the predecessor to the internet, a network called ARPANET.

On Oct. 29, 1969, Leonard Kleinrock and Charley Kline sent Stanford University researcher Bill Duval a two-letter message: “lo.” The intended message, the full word “login,” was truncated by a computer crash.