The Chief Constable of Northamptonshire Police is to retire in July, having completed 30 years service.
Adrian Lee joined Greater Manchester Police in 1985.
He joined Staffordshire Police as Assistant Chief Constable (Crime and Operations) in December 2003 with responsibility for crime support, criminal justice administration, the operations division and the communications centre.
He was appointed as Deputy Chief Constable of Staffordshire in December 2006 and took up his current post as Chief Constable of Northamptonshire on October 12, 2009.
Mr Lee said: “It has been a huge privilege to serve as the Chief Constable of Northamptonshire Police.
“The force has so many amazing men and women, serving in all capacities, who share my view about the importance of Vision, Values and Vocation in policing and work so hard to deliver the vision: to be the safest county in the country.
“Northamptonshire has led the way in adopting the new governance arrangements and Adam Simmonds, the Police and Crime Commissioner, and I have a joint commitment to seek the best for the people of the county.
“The Police and Crime Plan is enabling us to deliver better services at a time of significant financial constraint.
“To do that we have established ourselves as national leads on collaboration through our work with other forces in the East Midlands Region, other forces in the country, our work with Northamptonshire Fire and Rescue Service and with other county partners and stakeholders.
“I am proud of all that we have achieved together and the positive impact the force has had on so many lives. Strong foundations have been built for the challenges ahead.”
Mr Simmonds, who will now begin the task of appointing a new chief constable, said: “I am incredibly grateful for all his support, advice, consideration, grace and friendship over the past two years.
“He has shown considerable loyalty to our county and to the best principles of policing.
“The fine position of the force, our strategic plans and the direction of travel have been placed in such a good position through his leadership.
“I am very grateful for his dedication in making Northamptonshire Police the best it can be and getting us further on the journey towards Northamptonshire being the safest county in England.”