The Police Service of Northern Ireland was formed 25 years ago, replacing the Royal Ulster Constabulary. The anniversary is an opportunity to examine the force's current state and the role it and its predecessor played in the peace process.

Over 300 police officers lost their lives carrying out their duties during the Troubles. Thousands more were injured. The threat they faced came from those who operated in the shadows, placing bombs in ditches or under cars, shooting from a distance, or carrying out close-range executions without warning.

The reforms that created the PSNI were difficult for many who had served in the RUC. However, they eventually led to a police service that had political support from across both communities, although Sinn Féin's support was often half-hearted.

The PSNI operates in a changed Northern Ireland and a changed world compared to its predecessor. What has remained constant is the bravery of the men and women who wear the uniform and stand between the public and danger.