This is a 1600 copy of a 1558 portrait painted of 25-year old Elizabeth Tudor in her coronation robes with her regalia.
Biographicon has this about her accession, "... During her procession to the throne, she was welcomed wholeheartedly by
the common people, who performed plays and read poetry extolling her
beauty and intelligence. Elizabeth's coronation was on January 15,
1559. She was 25 years old. Since the senior bishops declined to
participate in the coronation because Elizabeth was illegitimate under
both canon law and statute, the relatively unknown Owen Oglethorpe,
Bishop of Carlisle crowned her. The communion was celebrated by
Oglethorpe, but a few weeks before the coronation, she demanded that he
not elevate the host, which the Bishop refused. Offended by this
intransigence, Elizabeth I walked out after the reading of the gospel.
Elizabeth I's coronation was the last one during which the Latin
service was used; future coronations except for that of George I used
the English service. She later made her mother's chaplain, Matthew
Parker, Archbishop of Canterbury..."
Upgrade image posted 3 March 2015 from Wikimedia; small spots removed from background with Photoshop.
Norris in Tudor Costume and Fashion, p.485 (Dover re-issue 1997), states - "The bodice, sleeves, and full skirt are of a golden yellow silk ground, the Renaissance pattern being worked in dull silver and seed pearls. The point of the stomacher is very long and outlined by a girdle of gold set with rubies, sapphires, pearls, and diamonds. A narrow band of ermine edges the cuffs of the close sleeves, and there is, no doubt, a deep border of the same fur surrounding the hem of the skirt. A small goffered ruff edged with gold, high at the back and narrow in front, encircles the face. The State mantle is very gorgeous. It is of cloth of gold covered with embroidery in colored silks incorporating red roses, grey-green leaves, and silver fleurs-de-lis and lined throughout with ermine; a deep collar or cape of the same fur is attached at the throat by long cords and tassels of gold. This cape is a substitute for the official hood, the latter being dispensed with on account of its bulk at the back of the neck; though it may be represented by a false hood lying flat on its back...The neck collar, shoulder collar or carcanet, girdle, orb, scepter, and very beautiful arched crown worn over her flowing hair, are set with rubies, sapphires, pearls, and diamonds...In an inventory of the Queen's wardrobe taken in 1600, her coronation robes were stated to have consisted of a dress with a long train of gold tissue lined with white sarcenet and bordered with ermine, worn over the Spanish farthingale."
Marileecody (http://www.marileecody.com/eliz1-images .html) has this
description: "c1600, unknown artist; copy of a lost original. This
portrait can be viewed at the NPG. This is a copy of the portrait made
to commemorate Elizabeth's accession in 1558. It is a stunning and
beautiful image. Elizabeth is lavishly dressed and holds the
traditional orb and scepter. Her hair is loose, as befits her unmarried
state, and its color is particularly striking against the white of her
skin. And, once again, Elizabeth's much-admired hands are prominently
displayed as they rest upon the symbols of her authority."
Keywords: 1558, Queen Elizabeth Tudor, Elizabeth I of England, Tudor family, Queen, English, straight coiffure, crown, high enclosing neckline, ruff, carcanet necklace, long sleeves, ruffled cuffs, rings, girdle, deep vee waistline, farthingale, robes, jeweled chain, fur lining, regalia