Pat Ennis, General secretary of the GRA: Dubliner Pat Ennis had a baptism of fire on the first day in his job.
A garda for over 30 years, he was appointed general secretary of the Garda Representative Association (GRA) on the same day the rank-and-file gardaí announced they would go on strike for four days next month.
He faced a backlash at a conference that day from delegates to a draft deal agreed by the association's negotiating team with the Department of Justice the previous Friday.
He has a tough act to live up to following PJ Stone's retirement earlier this year.
Members of the association credit his predecessor for having the gift of keeping the more militant members of its 31-member central executive committee in line.
Mr Ennis previously held the position of treasurer of the association and represented Garda Headquarters on the Central Executive Committee.
He spent much of his career with the Garda Technical Bureau.
John Jacob, General secretary of the AGSI
Offaly man John Jacob is probably best known for announcing he was prepared to risk jail for proposing strike action over pay claims.
He made the declaration at his association's annual conference in Westport last April and warned that the association, which had been conservative, had become militant.
He joined the force in 1982 and was originally a garda based in the Louth/Meath division. He was promoted to sergeant in 1994. He was promoted to the rank of inspector in 2008 and has worked in the 'Change Management' section at Garda HQ. He became deputy general secretary of the AGSI in 2013.
He has been an active member of the association's campaign to fight cuts to allowances and pay. One of his ambitions has been to encourage more active local membership.
He succeeded John Redmond as leader last year.
Kieran Christie, General secretary of the ASTI
ASTI general secretary Kieran Christie, from Sligo, is a teacher of design and graphics, materials technology and construction.
Although a long-time ASTI activist, his mild-mannered personality does not fit the mould of a firebrand presiding over the shutdown of 500 second-level schools.
The appointment, last year, of a working teacher as general secretary marked a break in the ASTI practice of selecting a candidate who had built a reputation as a full-time trade union official.
Mr Christie's predecessor, Pat King, went public a couple of years ago about abuse he had received on a website called Fightback, run and moderated by union members, who, he said, were trying to undermine the union leadership.
The ASTI has been riven with internal tensions for more than a decade, a period marked by the growth of a power base of hardliners, who are influential in pushing policy in an increasingly radical direction. It has left moderate ASTI activists concerned about where it will end.