Star Trek Phase II never happened. It was dropped in favor of making the ST films starting with ST:TMP in 1979.
The entire original cast had signed up with the exception of Leonard Nimoy. He was to be replaced by another actor playing a different Vulcan.
Interesting side note--the Enterprise in Phase II looked a bit like the one we have in the current ST films, it was partly original series looking and partly how it looked in TMP. They took the redesign further for the film. The bridge and many sets had already been made and were reused for the films, some design aspects still being visible as late as ST 3.
The Jedi Master
