There was a big difference in their ages, John was nearly thirty-four and Isabella was about fifteen when they married on the 24th of August 1200. The birth of their firstborn suggests that the king may have respected her tender age and stayed out of the marriage bed until at least the end of 1206.
Following their marriage, the couple arrived back in England, where on this day, the 8th October 1200, Isabella was crowned at Westminster Abbey.
The view that most historians put forward, that King John was a tyrant and a thoroughly bad chap with absolutely no redeeming features, makes it difficult to find anything positive to say about his twelve-year marriage to Isabella, but from what I have read it looks to be an exact copy of that of John's parents Henry II and Eleanor of Aquitaine. John was a philanderer, so was Henry, Isabella a been a strong and forceful woman, so was Eleanor.
Soon after John's death in 1216, Isabella left her children, the youngest just a year old, in the care of the English court, and made a new life for herself with a new husband in her home of Angouleme.