When did turboprops come into vogue?

I was reading my new Flying magazine today and it had an article
covering the decline of the 310/Seneca type light twins. It pointed
out that the performance ground previously addressed by a twin piston
is now covered by turbine powered aircraft. Being new to flying
myself vs riding in a fast bus I'm not well versed in GA history. I
was just curious to know when the single engine turboprop became a
true viable alternative.