What is a row of lights along the front of a stage at a theatre called?

Footlights, in theatre, row of lights set at floor level at the front of a stage, used to provide a part of the general illumination and to soften the heavy shadows produced by overhead lighting.

As first used on the English stage in the latter part of the 17th century, footlights consisted of open-flame oil lamps with floating wicks. A tin trough was later added to reflect the lights onto the stage and to shield them from the view of the audience. The lamps themselves were gradually improved, and footlights remained a major source of stage light until the first half of the 19th century, when high-intensity lights such as the limelight made it possible to illuminate the stage from the front.

Modern footlights, usually recessed into the floor of the stage, can be used to provide a soft, diffuse light that cuts any harsh shadows caused by the other forms of stage lighting and provides a bright yet natural setting for the actor. In the open stage footlights are not used.