Eleanor of Brittany, Queen of Sicily, England and France
Eleanor became fatherless at the age of two and was brought up by her uncle King Richard and grandmother Eleanor of Aquitaine. However, Richard's ward also meant that she was under Angevin custody, and thus even her mother Constance never considered her a potential heir to Brittany, which weakened her later claim to the duchy.
While Richard I was away on the Third Crusade, Arthur's mother Constance made actions to make the Duchy of Brittany more independent. On November 11, 1190, Richard betrothed Arthur to a daughter of Tancred of Sicily as part of their treaty and Eleanor of Brittany married to Roger III of Sicily, the junior King of Tancred in exchange for the liberty of Joan of England, the dowager queen of Sicily.
Sicily was claimed by Tancred's aunt Constance and her husband, Emperor Henry VI so the betrothal never happened. After he had conquered the Sicilian kingdom, Irene was captured on 29 December 1194 and was released by Philippe Auguste and married to Louis the Lion on 1199, her sister, Mafalda, Queen of Leon(Matilda of Brittany) was married on 1197 to the King of Leon.
The french reclaimed Normandy and the other fiefs of France after John I of Englnd erred by marrying Isabella of Angouleme, Aquitaine remained under John due to Eleanor of Aquitaine choosing him as heir
Arthur of Brittany died on 1204 while battling King John causing the french to annex Aquitaine, a short peace happened on 1204-1210, Eleanor gave birth to Philip III of France, Louis of Normandy and Eleanor of France at this point.
On 1210, the barons deposed John and chose Eleanor and Louis as the King and Queen of England, Louis ruled both England and France with Eleanor of Brittany since 1223 till 1227 when Louis died of disintery and Eleanor of Brittany exercised her powers as Queen Regnant of England, Duchess of Brittany from 1227 till 1241, her death.
Eleanor of Brittany m. Roger III of Sicily 1190 (a) m. Louis VIII of France 1199(b)
1b. Philip III b. 1205
2b. Eleanor of France b. 1207
3b. Louis of Normandy b. 1209
4b. Arthur of Rennes b. 1212
5b. Isabella of France b. 1215
6b. Charles of Anjou b. 1218
7b. William of Poiters b. 1222