The ARPANET, or Advanced Research Projects Agency Network, was one of the very first operational packet switching networks in the world and was also the first network to implement TCP/IP and the very foundations of what was to later become the global internet.

Funded initially by the Advanced Research Projects Agency situated within the US Dept. of Defence for exclusive use at universities and laboratories based within the United States.
The ARPANET packet switch was created by Paul Baran, an American engineer, Lawrence Roberts and Donald Davies, a Welsh scientist.

On this day, back in 1969 at exactly 10:30pm the very first message was sent via ARPANET from a computer belonging to Leonard Kleinrock at the University of California Los Angeles and was sent by a student programmer at the facility, Charley Kline. The message, which was simply, “Lo” was received by the Stanford Research Institute’s computer which was located at Menlo Park in California.

The message was originally meant to say “Login” but after the letters L and O were transmitted, the system unfortunately crashed and therefore the very first message that was sent over the ARPANET was just, “Lo”

However, after about an hour later, the system rebooted and the full message was sent between the two computers.

Moving forwards, the first ARPANET link was officially established back on the 21st November 1969 between the IMP at University of California Los Angeles and the IMP at the Stanford Research Institute and by the 5th Dec 2969, the entire four node network was completed and established.

Over the following years, the ARPANET grew from strength to strength, and in June 1974, less than five years after the first message was sent an astonishing 46 IMP’s had joined the network. This number continued to grow over the years.

However, due to evolving technology and factors being replaced by newer methods, the ARPANET was formally decommissioned on the 28th Feb 1990. Vinton Cerf wrote a lamentation which was aptly titles, “Requiem of the ARPANET”

“It was the first, and being first, was the best,
but now we lay it down to ever rest.
Now pause with me a moment, shed some tears.
For auld lang syne, for love, for years and years
of faithful service, duty done, I weep.
Lay down thy packet, now, O friend, and sleep.”
Image credit: //