James VI and I was King of Scotland as James VI from 24 July 1567 and King of England and Ireland as James I from the union of the English and Scottish crowns on 24 March 1603 until his death. The kingdoms of England and Scotland were individual sovereign states, with their own parliaments, judiciary, and laws, though both were ruled by James in personal union.
He succeeded to the Scottish throne at the age of thirteen months, after his mother Mary, Queen of Scots, was compelled to abdicate in his favour. Four different regents governed during his minority, which ended officially in 1578, though he did not gain full control of his government until 1583. In 1603, he succeeded the last Tudor monarch of England and Ireland, Elizabeth I, who died without issue. He continued to reign in all three kingdoms for 22 years, a period known as the Jacobean era after him, until his death in 1625 at the age of 58. After the Union of the Crowns, he based himself in England from 1603, only returning to Scotland once in 1617, and styled himself "King of Great Britain and Ireland". He was a major advocate of a single parliament for both England and Scotland. In his reign, the Plantation of Ulster and British colonisation of the Americas began.