Paternal Family Tree: Blois
Maternal Family Tree: Gerberge Unknown Viscountess Anjou
Lucia Mahaut Blois Countess Chester was born to Stephen Blois II Count Blois and Chartres and Adela Normandy Countess Blois. She a granddaughter of King William "Conqueror" I of England.
In 1080 [her father] Stephen Blois II Count Blois and Chartres [aged 35] and [her mother] Adela Normandy Countess Blois [aged 13] were married at Chartres [Map]. She by marriage Countess Blois. The difference in their ages was 22 years. She the daughter of [her grandfather] King William "Conqueror" I of England [aged 52] and [her grandmother] Matilda Flanders Queen Consort England [aged 49]. He the son of Theobald Blois III Count Blois [aged 68] and Gersenda Maine Countess Blois. They were third cousins.
In 1104 [her brother] William "Simple" Blois Count Blois Count Chartres [aged 19] and [her sister-in-law] Agnes Sully Countess Blois and Chartres [aged 19] were married. She by marriage Countess Blois, Countess Chartres. He the son of [her father] Stephen Blois II Count Blois and Chartres [aged 59] and [her mother] Adela Normandy Countess Blois [aged 37].
In 1107 [her future husband] Richard Avranches 2nd Earl Chester [aged 13] succeeded 2nd Earl Chester. Lucia Mahaut Blois Countess Chester by marriage Countess Chester.
In or before 1120 Richard Avranches 2nd Earl Chester [aged 25] and Lucia Mahaut Blois Countess Chester were married. She the daughter of Stephen Blois II Count Blois and Chartres [aged 74] and Adela Normandy Countess Blois [aged 52]. He the son of Hugh of Avranches 1st Earl Chester and Ermentrude Clermont Countess Chester. They were half second cousins. She a granddaughter of King William "Conqueror" I of England.
On 25th November 1120 the White Ship left Barfleur in north-west Normandy, with a party of young Normans. [her uncle] King Henry I "Beauclerc" England [aged 52] had left earlier on another ship. A mile out the White Ship foundered on a submerged rock. William Adelin Duke Normandy [aged 17], his half-siblings Richard Fitzroy [aged 19] and Matilda Fitzroy Countess Perche, William Bigod [aged 27], Lucia Mahaut Blois Countess Chester, brothers Geoffrey Aigle and Engenulf Aigle, half-brothers [her husband] Richard Avranches 2nd Earl Chester [aged 26] and [her brother-in-law] Ottiwel Avranches, brothers Ivo Grandesmil and William Grandesmil and Geoffrey Ridel were all drowned.
Chronicon ex Chronicis by Florence and John of Worcester. [25th November 1120] Shipwreck of king Henry's children. Henry, king of England, having successfully accomplished all his designs, returned from Normandy to England. His son William [aged 17], hastening to follow him, embarked in company with a great number of nobles, knights, women, and boys. Having left the harbour and put out to sea, encouraged by the extraordinary calmness of the weather, shortly afterwards the ship in which they were sailing struck on a rock and was wrecked, and all on board were swallowed up by the waves, except one churl, who, as it is reported, was not worthy of being named, but by the wonderful mercy of God, escaped alive. Of those who perished, those of highest rank were, William, the king's son, [her husband] Richard [aged 26], earl of Chester, [her brother-in-law] Othiel, his brother, William Bigod [aged 27], Geoffrey Riddel, Walter d'Evereux, Geoffrey, archdeacon of Hereford, the king's daughter, the countess of Perche, the king's niece, the countess of Chester, and many more who are omitted for brevity's sake. This disaster horrified and distressed the mind of the king, who reached England after a safe voyage, and of all who heard of it, and struck them with awe at the mysterious decrees of a just God.
Note 1. Ordericus Vitalis, in his twelfth book, c. xxv., gives a particular account of the shipwreck of the Blanche Nef; which is also mentioned, with more or less detail, by Huntingdon, Malmesbury, and other chroniclers.
History of the Dukes of Normandy by William of Jumieges. The daughter1 [Lucia] of Adela, daughter of King William of the English, of whom we have spoken above, was married to Richard, Earl of Chester, son of Hugh, Earl of Chester, and this Hugh was the son of Richard, Viscount of the region of Avranches. When Richard and his wife died in the oft-mentioned shipwreck together with William, son of King Henry, Ranulf2, Viscount of Bayeux, cousin of Richard, obtained his county. After the death of this Ranulf, his son, also named Ranulf, succeeded him, a man of great prowess in warfare. This same Ranulf's sister [Alice] was married to Richard [de Clare], son of Gilbert, by whom she had three sons. This Richard, as stated above [History of the Dukes of Normandy by William of Jumieges], was slain by the Welsh. The aforesaid Ranulf, Earl of Chester, took to wife Matilda [the manuscript reads Sibyl], daughter of Robert, Earl of Gloucester, by whom he begot two sons, Hugh and Richard.
Filia autem Adelæ filiæ Willelmi regis Anglorum, de qua superius fecimus mentionem, nupsit Richardo comiti Cestrensi, filio Hugonis comitis; qui Hugo fuit filius Richardi vicecomitis Abrincatensis pagi. Cum vero Richardus et uxor ejus in sæpe dicto naufragio cum Willelmo filio regis Henrici mortui fuissent, Ranulfus vicecomes Bajocasini, consobrinus ipsius Richardi, adeptus est comitatum ejus. Mortuo autem eodem Ranulfo, successit ei item Ranulfus filius ejus, vir in rebus bellicis strenuus. Hujus autem Ranulfi sororem duxit Richardus filius Gisleberti, ex qua suscepit tres filios. Ipse denique Richardus peremtus est a Walensibus, ut præfixum est. Prædictus autem Ranulfus comus accepit uxorem Mathildem [ms. Sibyllam] filiam Roberti comitis Glocestria; ex qua genuit duos filios, Hugonem et Richardum.
Note 1. Lucia of Blois, died 1120, daughter of Stephen, Count of Blois and Adela, daughter of King William the Conqueror. Lucia married Richard of Avranches, 2nd Earl of Chester, son Hugh of Avranches, 1st Earl of Chester, and Ermentrude of Clermont.
Note 2. Following the death of Richard, 2nd Earl of Chester, in the White Ship Disaster in 1120, his first cousin Ranulf, son of Richard's father's sister Margaret, succeeded to the Earldom of Chester.
Kings Wessex: Great x 6 Grand Daughter of King Edward "Elder" of the Anglo Saxons
Kings England: Grand Daughter of King William "Conqueror" I of England
Kings France: Great x 3 Grand Daughter of Hugh I King of the Franks
Kings Duke Aquitaine: Great x 7 Grand Daughter of Ranulf I Duke Aquitaine
Great x 4 Grandfather: Theobald "Elder" Blois 
Great x 3 Grandfather: Theobald "Trickster" Blois I Count Blois
Great x 2 Grandfather: Odo Blois I Count Blois 5 x Great Grandson of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Great x 4 Grandfather: Herbert II Count Vermandois, Soissons and Meaux 3 x Great Grandson of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Great x 3 Grandmother: Luitgarde Vermandois Duchess Normandy 4 x Great Granddaughter of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Great x 4 Grandmother: Adela Capet Countess Vermandois, Soissons and Meaux 
Great x 1 Grandfather: Odo Blois II Count Blois 3 x Great Grandson of King Edward "Elder" of the Anglo Saxons
Great x 4 Grandfather: Rudolph "Pious" II King Burgundy II King Italy
Great x 3 Grandfather: Conrad I King Burgundy
Great x 4 Grandmother: Bertha Swabia Queen Consort Italy
Great x 2 Grandmother: Bertha Welf Queen Consort France 2 x Great Granddaughter of King Edward "Elder" of the Anglo Saxons
Great x 4 Grandfather: Louis "Overseas" IV King West Francia Grandson of King Edward "Elder" of the Anglo Saxons
Great x 3 Grandmother: Mathilde Carolingian Queen Consort Burgundy Great Granddaughter of King Edward "Elder" of the Anglo Saxons
Great x 4 Grandmother: Gerberga Queen Consort West Francia
Grandfather: Theobald Blois III Count Blois 4 x Great Grandson of King Edward "Elder" of the Anglo Saxons
Great x 2 Grandfather: William IV Auvergne
Great x 1 Grandmother: Ermengarde Auvergne Countess Blois
father: Stephen Blois II Count Blois and Chartres 5 x Great Grandson of King Edward "Elder" of the Anglo Saxons
Great x 4 Grandfather: Hugh Maine I Count Maine 2 x Great Grandson of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Great x 3 Grandfather: Hugh Maine II Count Maine 3 x Great Grandson of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Great x 4 Grandmother: Rorgonide Countess Maine
Great x 2 Grandfather: Hugh Maine III Count Maine 4 x Great Grandson of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Great x 1 Grandfather: Herbert "Wakedog" Maine I Count Maine 5 x Great Grandson of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Great x 4 Grandfather: Judicael Berengar Penthièvre I Count Rennes
Great x 3 Grandfather: Conan "Crooked" Penthièvre III Duke Brittany
Great x 2 Grandmother: Unamed Penthièvre Countess Maine 7 x Great Granddaughter of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Great x 4 Grandfather: Geoffrey "Greygown" Ingelger 1st Count Anjou
Great x 3 Grandmother: Ermengarde Gerberga Ingelger Duchess Brittany 6 x Great Granddaughter of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Great x 4 Grandmother: Adele of Meaux Countess Anjou 5 x Great Granddaughter of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Grandmother: Gersenda Maine Countess Blois 6 x Great Granddaughter of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Lucia Mahaut Blois Countess Chester Granddaughter of King William "Conqueror" I of England
Great x 4 Grandfather: William "Longsword" I Duke Normandy 
Great x 3 Grandfather: Richard "Fearless" Normandy I Duke Normandy
Great x 4 Grandmother: Sprota
Great x 2 Grandfather: Richard "Good" Normandy II Duke Normandy
Great x 4 Grandfather: Unknown Dane
Great x 3 Grandmother: Gunnora Countess Ponthieu
Great x 1 Grandfather: Robert "Magnificent" Normandy I Duke Normandy 8 x Great Grandson of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Great x 4 Grandfather: Judicael Berengar Penthièvre I Count Rennes
Great x 3 Grandfather: Conan "Crooked" Penthièvre III Duke Brittany
Great x 2 Grandmother: Judith Penthièvre Duchess Normandy 7 x Great Granddaughter of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Great x 4 Grandfather: Geoffrey "Greygown" Ingelger 1st Count Anjou
Great x 3 Grandmother: Ermengarde Gerberga Ingelger Duchess Brittany 6 x Great Granddaughter of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Great x 4 Grandmother: Adele of Meaux Countess Anjou 5 x Great Granddaughter of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Grandfather: King William "Conqueror" I of England -2 x Great Grandson of King William "Conqueror" I of England
Great x 2 Grandfather: Father of Beatrix and Herleva
Great x 1 Grandmother: Herleva of Falaise
mother: Adela Normandy Countess Blois daughter of King William "Conqueror" I of England
Great x 4 Grandfather: Baldwin III Count Flanders Great Grandson of King Alfred "The Great" of Wessex
Great x 3 Grandfather: Arnulf II Count Flanders 2 x Great Grandson of King Alfred "The Great" of Wessex
Great x 4 Grandmother: Matilda Billung Countess Flanders
Great x 2 Grandfather: Baldwin "Bearded" IV Count Flanders 3 x Great Grandson of King Alfred "The Great" of Wessex
Great x 4 Grandfather: Berengar II King of Italy 
Great x 3 Grandmother: Rozala of Italy 5 x Great Granddaughter of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Great x 4 Grandmother: Willa Bosonids Queen Consort Italy 4 x Great Granddaughter of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Great x 1 Grandfather: Baldwin "The Good" V Count Flanders 4 x Great Grandson of King Alfred "The Great" of Wessex
Great x 4 Grandfather: Siegfried Count of Ardennes 4 x Great Grandson of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Great x 3 Grandfather: Frederick Luxemburg Ardennes 5 x Great Grandson of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Great x 4 Grandmother: Hedwig Nordgau
Great x 2 Grandmother: Ogive Luxemburg Countess Flanders 6 x Great Granddaughter of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Great x 4 Grandfather: Heribert I Count Gleiberg Gleiburg
Great x 3 Grandmother: Ermentrude Gleiburg
Grandmother: Matilda Flanders Queen Consort England Great Granddaughter of Hugh I King of the Franks
Great x 4 Grandfather: Hugh "Great" Capet Count Paris 4 x Great Grandson of Charles "Charlemagne aka Great" King of the Franks King Lombardy Holy Roman Emperor
Great x 3 Grandfather: Hugh I King of the Franks -2 x Great Grandson of Hugh I King of the Franks
Great x 4 Grandmother: Hedwig Saxon Ottonian
Great x 2 Grandfather: Robert "Pious" II King of the Franks son of Hugh I King of the Franks
Great x 4 Grandfather: William "Towhead" III Duke Aquitaine Great Grandson of Ranulf I Duke Aquitaine
Great x 3 Grandmother: Adelaide Poitiers Queen Consort France 2 x Great Granddaughter of Ranulf I Duke Aquitaine
Great x 4 Grandmother: Gerloc aka Adela Normandy Duchess Aquitaine
Great x 1 Grandmother: Adela Capet Duchess Normandy Granddaughter of Hugh I King of the Franks
Great x 4 Grandfather: Boson II Count Arles
Great x 3 Grandfather: William "Liberator" I Count Provence I Count Arles
Great x 2 Grandmother: Constance Arles Queen Consort France
Great x 4 Grandfather: Fulk "Good" Ingelger 2nd Count Anjou
Great x 3 Grandmother: Adelaide-Blanche of Anjou Queen Consort West Francia
Great x 4 Grandmother: Gerberge Unknown Viscountess Anjou