Boadicea

The Britannia was the original Latin name the Roman Empire gave to Britain.
Deriving from Pretannia, Diodorus's Greek rendering of the indigenous name pretani,
Britannia became the preferred Roman term for the islands and was personified as a Goddess by the Romans.

The original islands consisting of Albion (Britain), Hibernia (Ireland) and many smaller islands.
Over time, Albion came to be known as Britannia, and the name for the group was subsequently dropped.

There was a Celtic goddess called Brigid who is one of the many sources of the personification of Britain.
She is the goddess of all things perceived to be of relatively high dimensions such as high-rising flames,
highlands, hill-forts and upland areas. She was seen as to have been the Celtic equivalent of the
Roman Minerva and the Greek Athena, thus depicted as a beautiful young woman, wearing the helmet of a Centurion,
and wrapped in a white garment with her right breast exposed.

Britannia first appeared on a coin issued by Emperor Hadrian around 130 CE.
This image shows a seated woman with a spear across her left arm and resting her left elbow on a large bossed celtic shield.

Her bare left foot is visible, and she is dressed in Roman style. Her expression is one of sadness.

The Britannia of James I was used to unite his new kingdom,
and was seen standing with a small classical round shield and a Greek style sword.

In 1665, the artist Philip Roettier revived her image for the new copper coins based on
Hadrian's coin: Britannia is seated, bare left foot exposed, holding a spear in her left hand
and her left elbow rests upon a shield.

The shield is emblazoned with the Flag of the Union (no cross of St Patrick in it), and her right hand,
rather than supporting her chin - now holds a branch of olive leaves.

So to the Netherlands - The seated image we have today was taken from the Dutch, and arrived with William of Orange,
it is the image of Propartia - In 1579, a number of the northern Netherlands signed the Union of Utrecht,
in which they promised to support each other in their defense against the Spanish army.

They chose a symbol of a woman sitting in a round fenced garden, with a a small standing lion holding
a fachista of arrows and a sword.

The combined image was applied to bank notes, the first of which appeared in 1694.
Britannia with her new pet lion, sitting on looking on a beehive - used to represent either the bank or industry.

The Hanovarian Georges adopted this symbol,
and changed the lion to a sleeping one, and made the 'Dutch' girl look a bit more classical, with Minerva's helmet.

Queen Victoria added the union Jack to the shield, and gave her a trident, to symbolised the royal Navy.

Source : David C, Yahoo UK & Ireland