Original: A collaboration between local activists and campaigners and academics from the Department of History, University of Sheffield.
Simplified: A union between local activists and campaigners and academics from the Department of History, University of Sheffield.
Simplified: Local activists, campaigners  and academics from the Department of History at the University of Sheffield will be working together.
Simplified: A combination between local activists and campaigners and academics from the Department of History, University of Sheffield.