He invented the "secret rapture".
Chiliasm (millennialism) had existed since the second century.
Darby was the first to teach that God still had a plan for Israel, that the plan for Israel had been put on hold, and that a secret parenthetical dispensation (time period) had been inserted with God's plan for Israel.
Zionism had also already existed before Darby.
Basically, Darby invented the secret rapture as a way for the people of the secret parenthetical time period to be removed from planet earth so God could pick back up with Israel.
No one taught this rubbish before Darby.
Darby was not the first.
But why arm your ignorance even further?