Michelle O'Neill has been involved in republican politics from her teens, has held various senior positions within Sinn Fein and has a background in social welfare issues.
Mrs O'Neill was elected to the devolved Assembly in 2007 following the restoration of powersharing after years of back-room work for former assembly member Francie Molloy.
The mother-of-two was the first woman to hold the position of mayor of Dungannon and South Tyrone Borough Council and also one of the youngest.
While agriculture minister she decentralised government services from Belfast and won praise for efforts to boost rural development - although a DUP ministerial colleague won a court challenge against her bid to divert funds towards that area.
-- Sinn Féin (@sinnfeinireland) January 29, 2018
One of her first actions as health minister was to lift the lifetime ban on gay men donating blood.
She has also supported a cross-border cardiology service credited with saving the lives of 27 patients from Co Donegal in its first nine months.
Her father, Brendan "Basil" Doris, was a former IRA prisoner who became a Sinn Fein councillor in Dungannon.
Her uncle, Paul Doris, is president of Noraid, a republican fundraising group.
However, unlike Martin McGuinness or Gerry Kelly, she had no direct IRA involvement.