When Duke John died of plague in 1348, Elizabeth became the regent for ten-year-old Louis. Elizabeth's regency lasted from 1348, until her death. Her daughter Constance took over as regent for Louis.
Upon the death of Duke John from the plague in 1348, Elizabeth took charge of Louis, who was just ten years old at the time. She governed on his behalf until her own passing. Subsequently, her daughter Constance assumed responsibility for Louis.