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.