For 10 points, name this woman who struggled against Stephen of Blois, the first female ruler of England.
An attempt to crown this ruler was thwarted by opposition that sprung up in London as a result of the decision to impose additional taxes. A fake story about this ruler's father having a deathbed change of heart, despite forcing his prelates to swear loyalty to this ruler three times, was used to get the Archbishop of Canterbury to crown a rival. In the wake of the accession of William Clito, this ruler's second marriage was negotiated in an alliance with Count Fulk V. This ruler supposedly used a white cape as a disguise in the snow to escape Wallingford Castle, where a later treaty secured the rulership of England for this ruler's son. Robert of Gloucester (*) was the half-brother and primary commander of the forces of of this ruler, whose brother died in the White Ship Incident, prompting the father of this wife of Geoffrey Plantagenet to attempt to secure her succession to the throne. For 10 points, name this woman who struggled against Stephen of Blois, the first female ruler of England.
An attempt to crown this ruler was thwarted by opposition that sprung up in London as a result of the decision to impose additional taxes.
Empress Matilda [or Matilda of England; or Maude]