The organisation is advertising for a leader on a six-figure package to replace Frances Done.
Done, the first woman and the first person who has not served in the armed forces to lead the charity, became interim director-general after David Wills resigned for personal reasons in December.
Wills, whose departure was not announced publicly, had been in the post for only three months. He replaced long-serving director-general Ian Townsend.
Stuart Gendall, director of communications at the Royal British Legion, said it could take six months to fill the position, but denied the rapid changes at the top of the organisation had caused instability. "It has been managed in a professional and ordered way," he said.