There are several good beginner's/intermediate C++ books that describe how this language was formed (e.g. "C&C++ Code Capsules" by Chuck Allison). This is the story in a nutshell. . .

Bjarne Stroustrup, from Denmark, has a Ph.D. from Cambridge University (in England). While he was working for AT&T Bell labs, he was using Simula but found the performance lacking. He decided to use C as the basis for a new language that also had classes similar to Simula. His creation was originally called C with Classes. It caught on at AT&T where it was renamed C++. Eventually, an ANSI committee took over the development and "standardized" the language.

Of course, the creation and development was more complex than this. If you need more information, maybe someone can recommend some more books and other references.

If you buy the following book you can read al about the history of C++ starting even before the development of C.

The Title is C++ Programming Language (Third Edition)written by Bjarne Stroustrup.

I don't know if there is a newer edition of the book.
In my version of the book it is paragraph 1.4.