Guy (also Guido or Wido, died 929) was the count and duke of Lucca and margrave of Tuscany from 915, the death of his father Adalbert II, to his own death. He was originally under the regency of his mother Bertha, daughter of Lothair II of Lotharingia, until 916. He kept court at Mantua around the year 920. In 924 or 925, he became the second husband of Marozia, senatrix patricia Romanorum. He had one daughter, Theodora (or Bertha), and probably a few other children of which nothing else is known. None of his children survived him and he was succeeded in Tuscany by his brother Lambert.
| Preceded by Boso |
Margrave of Tuscany 915 – 929 |
Succeeded by Lambert |
