Frances Fitzgerald's political career: She promised a new era for policing

"This is a new era and new culture so the Irish people and Irish citizens can have confidence in our policing system," Mrs Fitzgerald declared with confidence, as she took on the biggest challenge of her political career.

Three and half years later, having apparently navigated her tenure in a job seen as the cabinet's poisoned chalice, the 67-year-old politician had surely pause to reflect on those words as she tendered her resignation as Tánaiste, having been brought down by the very same whistleblower crisis.

Mrs Fitzgerald, the Limerick-born daughter of an Irish Army officer, had a career as a social worker and family therapist, working in inner city areas of Dublin and London, before entering the political arena.

Her public profile had already been on the rise prior to her first election victory in 1992.

She had been chair of the Council for the Status of Women - now known as the National Women's Council - and the Women's Political Association and had become a vocal advocate for rape victims in Ireland.

A graduate of the University College Dublin and the London School of Economics and married to eminent child psychiatrist Michael Fitzgerald, she joined Fine Gael inspired by her namesake, former Taoiseach Garret FitzGerald, and secured a seat in the Dáil as TD for Dublin South East.

Her journey toward high office was not straightforward and, within a decade, her political career seemingly lay in tatters after losing her seat in what was a disastrous 2002 election for Fine Gael.

The mother of three sons narrowly missed out on winning it back in 2007, having also failed to secure a nomination to run for Fine Gael in the European and local government elections.

Missing out on a Dáil return, she took a seat in the Seanad and it was there her political renaissance began.

Appointed leader of the Seanad opposition, she developed a close working relationship with party leader Enda Kenny.

It was an alliance that would serve her well when the veteran Mayo TD swept to power in 2011 in the wake of the economic crash.

Mrs Fitzgerald, who secured a return to the Dáil having switched to run in the Dublin Mid West area, became one of Mr Kenny's trusted allies in government. She was handed the role of minister for children and youth affairs.

During her tenure, she oversaw the creation of Ireland's child and family agency Tusla, and a referendum that bolstered provisions for the rights of the child in the Constitution.

Having forged a reputation as a safe pair of hands, her appointment as justice minister came as no surprise following Mr Shatter's controversial departure.

Issues around Garda accountability, encapsulated by the damaging claims of malpractice made by whistleblower Maurice McCabe, dominated her in-tray throughout her three-year stint in the job.

She was battered by further revelations about Mr McCabe's treatment by the state; a scandal about falsified drink drive figures; and a bloody gangland feud that claimed more than a dozen victims.

But she appeared to have weathered those storms, notching up some notable achievements along the way.

She counted the passing of legislation to legalise same-sex marriage in 2015 as her proudest political moment while she also introduced measures to provide enhanced Garda oversight through the creation of the Policing Authority.

In May 2016 she was appointed Tánaiste, while retaining the justice brief.

But if she thought she had left the whistleblower furore behind her when she finally left the justice department in June 2017, she was wrong.

Having supported Leo Varadkar's leadership bid to succeed Mr Kenny, she was retained as Tánaiste when the new-look administration was put together.

The justice job was passed to another party veteran, Charlie Flanagan, as she took on a new role as Minister for Enterprise and Innovation.

But it was her actions, or inactions, in justice that returned to haunt her.

The whistleblower scandal has claimed yet another scalp - and it may not be the last.