Matilda was born in Winchester about 1102 and may have been a twin with her brother, William. Diplomacy had her engaged in 1109 to Emperor Heinrich V and she was married to him in 1114 when just over ten years old. Eleven years later the Emperor died, leaving her a childless widow.

In 1120 her brother drowned and, in 1126, she was declared heir to her father. In the following year her father married off the Empress, then about twenty-four years of age, to the fourteen-year-old Geoffrey, Count of Anjou. Although apparently somewhat reluctant, she
nevertheless bore three sons to him.
In 1135 her father died and she was supposed to have become Queen-regent. However, her cousin, Stephen de Blois, stepped in and, even though he had sworn to support Matilda, went to London where, with the support of the London citizens, he was crowned king on St.Stephen's
Day 1135.
Pope Innocent II acknowledged Stephen who bribed a great many of the barons as well as Matilda's uncle, David I, King of Scots. In the ensuing civil wars, Matilda was supported by her illegitimate half-brother, Robert, Earl of Gloucester. In February 1141, Stephen was captured and imprisoned at Bristol and so, on 7 April 1141, Matilda was proclaimed "Lady of the English". However, Stephen's supporters captured the Earl of Gloucester and had the two exchanged.
Stephen had himself re-crowned and the civil war continued.
In 1144 Normandy was taken by Geoffrey of Anjou, Matilda's husband. In 1148 Stephen feuded with the pope and, in 1153, Matilda's son, Henry, by now twenty years old, took Matilda's place while Matilda retired to Normandy. In 1153 a treaty was signed at Westminster by which it was decided that Stephen would remain king for life and Henry would be his successor. In 1154 Stephen died and Matilda, who remained in Normandy, survived until 1167 when she died at Rouen.
 

Source: Leo van de Pas