Baroness Pauline Neville-Jones, a senior figure in Government cyber operations, has quit as minister of state for security and counter terrorism.
Neville-Jones, who was one of the driving forces behind initiatives such as the Cyber Security Challenge UK, has now been appointed as a "special representative to business on cyber security."
Baroness Angela Browning has been appointed Lords minister of state at the Home Office, although it was not made clear whether she would take over Neville-Jones' duties as security and counter terrorism minister.
At the start of the year, Neville-Jones told Prime Minister David Cameron she wished to leave her post around the time of the local elections, letters between the two revealed.
In her letter to Cameron, Neville-Jones said she looked back on her time in the Coalition "with some satisfaction."
"When I accepted the post of minister for security and counter terrorism I hoped that I would be able to contribute in particular to the implementation of the policy issues on which I had worked while we were in opposition. And I am pleased that I have been able to do this," she said.
"Cyber security is now established as a front line priority for the Government indeed for the country as a whole and serious work is in hand on developing a long term strategy."
In his own letter, Cameron said Neville-Jones had successfully ensured "security and liberty are more appropriately balanced."
"You have also rightly insisted that cyber security should receive greater attention, which is now happening," he added.
Neville-Jones' year in office was not without its difficulties. She reportedly had tense relationships with other Government officials, including Home Secretary Theresa May.
There were moments regarded as embarrassing, too. On one occasion, she appeared to have forgotten the name of a Home Office official advising her, the Guardian noted.
At another time, when appearing before the Commons home affairs select committee, Neville-Jones seemed poorly prepared when discussions on the Government's replacement for control orders came up.
