Dickinson becomes the first to leave Lane
Dickinson has risen to captain at Rotherham since making his debut in 2009, having signed from Caldy.
Other announcements will follow with Sean Dougall, Robin Copeland, Semisi Taulava and Rob O’Donnell expected to move on.
Dougall is to join Munster, Copeland will sign for Cardiff and Taulava and O’Donnell have both agreed deals with Worcester.
But coach Andre Bester says it’s not the end of the world.
“It’s part of the process here that players will develop and move on,” he said.
“The job is to find replacements who will be even better and I already have a short list of potential recruits.”