Gendall, who has been in the top role for a decade, stepped down due to personal reasons.
Stepping into the breach is Robert Lee, formerly head of media and campaigns and now acting assistant director corporate communications.
The news follows on from a string of successful campaigns overseen by Gendall in recent years, including the recent 2 Minute Silence and a charity single containing no audio which made it into the top 20.
Lee has worked at The Royal British Legion for five years and has a career taking in broadcast journalism, as well as working in external relations for Petro-Canada in London and Moscow.
On the impact of Gendall’s departure, he said: ‘I think the direction of travel will not change for The Royal British Legion. We are all about making our message contemporary, relevant. The British public is happy wearing the poppy and we want them understanding why they are wearing it and where the money goes. This is the main part of our comms strategy and that will continue.’
Former Marconi internal communications head Gendall took on the role in 2002, replacing Charles Lewis.