Mr Hugh Orde takes up office at a pivotal moment for policing in the North.
The PSNI was formed out of the old RUC in November 2001, the transformation led by the former chief constable, Sir Ronnie Flanagan, and latterly by the caretaker chief officer, Mr Colin Cramphorn.
Mr Orde, a former deputy assistant commissioner with the London Metropolitan Police, was selected to lead the new service under new criteria by the Policing Board.
He faces daunting challenges ranging from police organisation and resources to public confidence and controversies still raging from RUC days.
According to the outgoing acting chief constable, the new service is vastly under-resourced. Mr Orde agrees. The service is recruiting heavily but time will be needed to get up to strength. The incoming Chief Constable will also push for the establishment of a police college and may seek retention for the time being of the full-time Police Reserve which Patten recommended be abolished.
He will also have to address a poor officer attendance rate, low morale and demands for greater "civilianisation" of clerical posts.
Old controversies continue to take their toll, both on resources and morale. Only one conviction has come from the Omagh investigation and the first police inquiry into the "Real IRA" bombing of 1998 was heavily criticised by an internal police report and by the police ombudsman.
The Stevens inquiry, which used to be led on a day-to-day basis by Mr Orde, is expected to report by November. Mr Orde has promised it will pull no punches and claimed it will not make happy reading.
Whether it settles questions relating to alleged collusion with loyalist paramilitaries in the cases of controversial murders, including that of Mr Pat Finucane in 1989, remains to be seen.
Mr Orde will now lead a police service which is perhaps the most scrutinised of any. He is answerable to the Policing Board, two members of which have publicly stated they do not believe he is up to the job. Mr Orde laughs this off. Sinn Féin continues to boycott the board, but has hinted it could participate following a legislative review by the British government. One Ulster Unionist says his party will consider withdrawing from the board if concessions are made to Sinn Féin to get it to take its seats.
The police will also be held to account by the police ombudsman, Ms Nuala O'Loan. Mr Orde welcomes this close attention and is familiar with some of Ms O'Loan's detectives.
He will also have to take account of reports filed by the police oversight commissioner, Mr Tom Constantine. Mr Constantine has already voiced concern that elements of the Patten report have not been addressed quickly enough. In particular, he has cited the need for Special Branch to be amalgamated with Crime Branch.
Mr Orde will have to take account of this and the wider question of intelligence gathering following the Castlereagh robbery.