Earliest full-length portrait of Queen Elizabeth I revealed - showing her as studious and shy young woman

She came to be known as the Virgin Queen, the commanding female monarch who defeated an Armada and launched Britain on its imperial adventures.

But in this portrait Queen Elizabeth I appears to be little more than a diminutive and shy young woman.

Discovered by Philip Mould, the BBC historian and art dealer, the painting - thought to be the earliest full-length portrait of the Queen - is now going up on display for the first time.

Critics are fascinated by the painting as it shows a rarely seen softer, more feminine and even petulant side of Elizabeth's character.

The portrait, painted on the wood of an oak tree, is believed to date from 1559 as experts have studied the tree's growth rings. Elizabeth came to the throne in 1558 and reigned for 45 years.

Experts restored the painting and after removing layers of paint from earlier attempts they uncovered parts of the original image such as the prayer book in her hand and ermine on her robe.

Mr Mould, who presents the BBC's Fake or Fortune programme, told The Telegraph: "I have yet to conclude, but it appears to be the earliest or possibly only full-length portrait of Elizabeth as Queen.

"This image is interesting as it belongs to a clutch of images of Elizabeth when she is first Queen. It shows a diminutive quite studious looking girl, noticeably thin holding a prayer book.

"She is so unlike what we usually associate with a Queen such as Elizabeth, she is earnest and solemn in this portrait. She was a real survivor at this point."

Mr Mould discovered the painting and received a huge amount of interest from the art trade and public when he posted a picture of it on his Twitter account.

He has now decided to put the portrait on display at his Pall Mall gallery in London from Monday.

Mr Mould added: "One of the reasons that so few portraits of this period exist is that Elizabeth sought to control her image.

"She probably disliked images like this as she started to use art to project her power and sovereignty.

"In her reign Elizabeth designed edicts to control the quality of images of her and she was known to knock into pieces and hurl into the fire images she did not like.

"She understood the power of art with the same intuitive power that politicians like Boris Johnson, Harold Wilson, and Margaret Thatcher understand the importance of image.

"Elizabeth understood the importance of her female images with the same intuition that Margaret Thatcher did, as Thatcher understood Elizabeth."

The last Tudor monarch's reign is seen as a golden age of English history with the defeat of the Spanish Armada in 1588 long held as one of England's greatest military achievements.

Elizabeth, who died in 1603, refused to marry and provide an heir, leaving the throne open for Protestant James VI of Scotland, the son of Mary, Queen of Scots, Elizabeth's cousin.