Roger I also called Bosso and the Great Count, was the Norman Count of Sicily from 1071 to 1101. He was the last great leader of the Norman conquest of southern Italy.
Roger was the youngest son of Tancred of Hauteville by his second wife Fredisenda. He arrived in Southern Italy soon after 1055.
Roger's first marriage took place in 1061, to Judith, daughter of William, Count of Évreux and Hawisa of Échauffour. She died in 1076, leaving all daughters:
A daughter, married Hugh of Gircea (died 1075/6), the first count of Paternò
Matilda (1062 – before 1094) married firstly (repudiated before 1080) as his second wife, Robert, Count of Eu married secondly (1080, divorced 1088) as his second wife, Raymond IV of Toulouse
Adelisa (died 1096), married in 1083 to Henry, Count of Monte Sant'Angelo
Emma (died 1120), briefly engaged to Philip I of France; married firstly William VI of Auvergne and secondly Rudolf, Count of Montescaglioso.
In 1077, Roger married a second time, to Eremburga of Mortain, daughter of "William, Count of Mortain" (probably William Warlenc). Their children were:
Mauger, Count of Troina
Matilda, married Guigues III, Count of Albon
Muriel (died 1119), married Josbert de Lucy
Constancia, married Conrad of Italy
Felicia, married King Coloman of Hungary
Violante, married Robert of Burgundy, son of Robert I of Burgundy
Flandina, married Henry del Vasto
Judith (died 1136), married Robert I of Bassunvilla
Roger's third and last wife was Adelaide del Vasto, niece of Boniface, Lord of Savona. They married in 1087. Their children were:
Simon, Count of Sicily
Matilda, married Ranulf II, Count of Alife
Roger II, Count, later King, of Sicily
Maximilla, married Hildebrand VI (of the Aldobrandeschi family)