Right. The apostles.
The POPE came hundreds of years later. As did Islam.
The apostles were not the rock Jesus was referring to. Rock=Peter=Kephas=Cephas
A little knowledge of Greek and Aramaic will show that.
Peter was the first Pope as only he was given the keys to the kingdom of Heaven. Keys represent an office - Jesus was instituting the Papacy here. Read about Eliakim in Isaiah to see what the keys and the other language in Matthew is referring to.