The rightful heiress to the crown of England was Henry I's daughter Matilda but at the time of Henry's death she was with her husband in Anjou and Stephen was the first to reach London and successfully claim the throne. Matilda or Maud, as she was also known, disputed Stephen's claim. Matilda's illegitimate half brother the 1st Earl of Gloucester rebelled, and civil war broke out in 1139 when Matilda invaded. In April 1141 hostile troops seized Stephen at the Battle of Lincoln but in November exchanged him for Gloucester who had been imprisoned by Stephen's supporters. Stephen then regained much lost power and in 1148 Matilda left England. Upon Maud's death, her son Henry Fitz-Empress continued the challenge. While the dispute continued, Henry married the divorced wife of the French King. This gave him great power as his wife was, in her own right, a reigning Princess. Stephen had married Matilda of Boulogne and hoped that their son Eustace would succeed him, however Eustace died and in 1153 at Winchester, Stephen reluctantly declared Henry Fitz-Empress as his heir. Stephen died of a heart attack in 1154.
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