King Stephen’s early reign was marked by fierce fighting with English barons, rebellious Welsh leaders and Scottish invaders. Following a major rebellion in the south-west of England, Matilda invaded in 1139 with the help of her half-brother Robert of Gloucester.
Neither side was able to achieve a decisive advantage during the first years of the war; the Empress came to control the south-west of England and much of the Thames Valley, while Stephen remained in control of the south-east. The castles of the period were easily defensible, and so the fighting was mostly attrition warfare, comprising sieges, raiding and skirmishing between armies of knights and footsoldiers, many of them mercenaries.
While Stephen and his army besieged Lincoln Castle at the start of 1141, Robert of Gloucester and Ranulf of Chester advanced on the king’s position with a somewhat larger force. When the news reached Stephen, he held a council to decide whether to give battle or to withdraw and gather additional soldiers: Stephen decided to fight, resulting in the Battle of Lincoln on February 2, 1141. Stephen was captured following the Battle of Lincoln, causing a collapse in his authority over most of the country.
Robert of Gloucester, Matilda’s half brother, took Stephen back to Gloucester, where the king met with the Empress Matilda, and was then moved to Bristol Castle, traditionally used for holding high-status prisoners. He was initially left confined in relatively good conditions, but his security was later tightened and he was kept in chains. The Empress now began to take the necessary steps to have herself crowned Queen of England in his place, which would require the agreement of the church and her coronation at Westminster.
Archbishop Theobald of Canterbury was unwilling to declare Matilda queen so rapidly, and a delegation of clergy and nobles, headed by Theobald, travelled to see Stephen in Bristol and consult about their moral dilemma: should they abandon their oaths of fealty to the king? Stephen agreed that, given the situation, he was prepared to release his subjects from their oath of fealty to him.
The clergy gathered again in Winchester after Easter to declare the Empress “Lady of England and Normandy” as a precursor to her coronation. While Matilda’s own followers attended the event, few other major nobles seem to have attended and a delegation from London prevaricated. Queen Matilda wrote to complain and demand Stephen’s release. The Empress Matilda then advanced to London to stage her coronation in June, where her position became precarious.
Despite securing the support of Geoffrey de Mandeville, who controlled the Tower of London, forces loyal to Stephen and Queen Matilda remained close to the city and the citizens were fearful about welcoming the Empress. On 24 June, shortly before the planned coronation, the city rose up against the Empress and Geoffrey de Mandeville; Matilda and her followers only just fled in time, making a chaotic retreat to Oxford.
King Stephen gained control of the country once again and the two warring parties reached an agreement. The agreement between the two factions was that Matilda’s eldest son, Henry Fitzempress, would succeed as King of England upon the death of King Stephen.
When Stephen died on October 25, 1154, Matilda’s son became King Henry II of England. Matilda retired to Normandy and held court when her son was abscent from Normandy. She died in 1167 and was clearly the legal successor to her father. Since she was the legal heir and given the fact the she briefly held London when Stephen was captured and imprisoned, many consider her the first true Queen Regnant of England.