Development of Lotus Notes started in 1984 by a company named Iris and release 1.0 ultimately saw the light in 1989. It was released by a company named “Lotus Development Corporation”.
“Release 1.0 saw the light in 1989”
Lotus Notes 1.0 screen 
Lotus Notes 1.0 public release 1989-12-07
From those very first days, a strong emphasis was made on security. Today this is still one of the major strengths of the product.
With release 3.0 in 1993, Lotus implemented a concept that is still quite unique today : replication. It allowed both online and offline work on data shared among different people. This is only one example of a long list of state-of-the-art features introduced during Notes/Domino’s lifetime.
In 1995, IBM bought the Lotus Corporation and became the ‘Lotus Development’ division. It allowed the software suite to make its way to large Fortune 500 companies and to become a market leader in collaboration software.
“In the years 2000, Lotus Notes/Domino became market leader in collaboration software.”
The brand ‘Lotus’ disappeared in 2012 and the official naming became IBM Notes (client software) in combination with IBM Domino (server) as we still know it today.
Despite lots of rumors around the death of IBM Notes/Domino in the last few years, the brand is still alive and kicking. The World Premiere of Notes/Domino V10 is on October 9th 2018. It is the result of the fruitful collaboration between IBM and HCL Technologies.
“Release 11 is on the roadmap.”
On December 6th 2018, IBM announced the full take-over of Notes/Domino – along with Sametime, Traveler and a few other products – by HCL Technologies. The transaction is foreseen for mid-2019.
https://www.ibm.com/developerworks/lotus/library/ls-NDHistory/index.html