The invading Normans took only a few years to conquer England after the Battle of Hastings in 1066. But Wales held out for two-and-a-half centuries.

Kidwelly Castle is a symbol of this enduring conflict. And it was here in 1136 that a warrior princess turned herself into one of Welsh history’s greatest heroines.

Gwenllian was authentic Welsh royalty – sister of the northern prince Owain Gwynedd and wife of Gruffudd ap Rhys, lord of Deheubarth. But she definitely didn’t live the life of a pampered princess.

Under constant threat from the Normans she was forced to hide away in the deep forests, where she raised four sons. Her husband was busy building an army and plotting lightning raids. But he chose the wrong time to head north for help.

In his absence Maurice de Londres, lord of Kidwelly Castle, began to gather forces for a counter-attack. He had to be stopped. So Gwenllian donned her battledress and entered the field herself.

She was ‘like some second Queen of the Amazons’, said the admiring historian Gerald of Wales. Some call her the Welsh Boudicca – the only woman to lead a medieval Welsh army into battle.

But they were no match for the Normans. She was captured and beheaded for treason. It’s said a spring welled up where she died – still known as Maes Gwenllian, or the Field of Gwenllian.

Her death wasn’t in vain. She inspired a popular uprising that swept the Normans out of West Wales. Finally true poetic justice was achieved by her youngest son, Rhys ap Gruffudd, who was just four years old when his mother died.

The Lord Rhys, as he was later known, captured Kidwelly Castle in 1159 and was recognised by King Henry II as the undisputed ruler of the region. But his death in 1197 provoked a power struggle. Just four years later the castle was back in Anglo-Norman hands.

You can pay tribute to brave and beautiful Princess Gwenllian at her monument near the castle gatehouse. You might even spot the headless ghost that’s reputed to stalk the grounds.