Hugh or Hugo (before 855 – 895) was an illegitimate son of Lothair II, king of Lotharingia, by his mistress Waldrada.
Hugh's name was not a Carolingian royal name, but it was common among the Etichonid family of Alsace, who were rumoured to be his mother's relatives.
After Lothair repudiated his wife, Teutberga, shortly after their marriage in 855, he sought to have his relationship with Waldrada and his children with her, including Hugh, legitimized.
[1] This would become a continuing theological and political struggle, as the laws and opinions around marriage and infidelity at this time were not solid.
It was in this situation that Lothair gave his son the duchy of Alsace during a stay at the court of Louis of East Francia.