Siege of Oxford
1142 CE.
Shown on the map at 51.752°, -1.258°.
The siege of Oxford took place during the Anarchy, a period of civil war following the death of Henry I of England without a male heir, in 1142. Fought between his nephew, Stephen of Blois, and his daughter, the Empress Matilda (or Maud), who had recently been expelled from her base in Westminster and chosen the City of Oxford as her new headquarters. Oxford by now was effectively a regional capital and important in its own right. It was a well-defended city with both rivers and walls protecting it, and was also strategically important as it was at a crossroads between the north, south-east and west of England, and also not far from London. By now the civil war was at its height, yet neither party was able to get an edge on the other: both had suffered swings of fate in the last few years which had alternately put them ahead, and then behind, their rival. Stephen, for instance, had been captured by Matilda's army in 1141, but later in the year, Matilda's half-brother and chief military commander, Robert, Earl of Gloucester was captured by Stephen's army.
Text from the Wikipedia article Siege of Oxford (1142), licensed CC BY-SA 4.0.