sentences:  Executive director and founder Spenceley and non-executive director Tony Grist left the board of Vocus in October 2016 after a failed leadership succession proposal.In February 2018 CEO Geoff Horth left the company.In March 2018 M2 Group Founding MD and CEO Vaughan Bowen stepped away from the role of Non-Executive Chairman of the Vocus Board to increase Board independence, and former Telstra Chairman and founding CEO of Optus, Robert Mansfield AO was made Chairman.