Why did James take the thown after Queen Elizabeth?

Answer 1

James was her closest relative. King Henry VII had 4 children
Arthur, Prince of Wales (19/20 September 1486 - 2 April 1502) who died without issue, Margaret Tudor Queen of Scots (28 November 1489 - 18 October 1541) married the king of Scotland Had two children that lived King James V and Margaret Douglas by Margaret's second husband Archibald Douglas, 6th Earl of Angus.
Henry VII's 3 child was King Henry VIII(28 June 1491 - 28 January 1547), Henry VIII had 3 Children Mary I (18 February 1516 - 17 November 1558), Elizabeth I (7 September 1533 - 24 March 1603), and Edward VI (12 October 1537-6 July 1553), all of Henry VIII's children died with out issue.
the 4th child of Henry VII was Mary Tudor, who had 2 children, Frances Grey, Duchess of Suffolk and Eleanor Clifford, Countess of Cumberland




Margaret Tudor's Son King James V had one Son James the VI who had one child Mary Queen of Scots, Mary married Margaret Douglas's son Henry Stuart, Lord Darnley and together they had a son King James VI. James VI of Scotland was the senior member of the senior Line from Henry VIIhowever it's not that easy, because when Henry VIII was dying he was giving the power to will the crown, Henry VIII willed the Crown first to Edward VI, he died childless so Henry VIII's will passed the Crown to Mary I, she died Childless so the Will passed the Crown to Elizabeth I, who also died Childless, now at the time of Henry VIII's dead (and the writing of HenryVIII's Will) Scotland and England were at war and Henry VIII was scared of the Scottish Kings taking the Crown, thus in the Will of Henry VIII his sister's line was skipped over in favor of his younger sister Mary's line. however by the time of Queen Elizabeth I's Death the Line of Mary Tudor was in a bad way. Mary Tudor's first born child Frances Grey, Duchess of Suffolk was mother of Lady Jane Grey(the Nine Day Queen) who was a key part of a coup against Queen Mary I, Frances Grey's other children Lady Catherine Grey and Lady Mary Grey got married without Queen Elizabeth I's say so, a crime for some one so close to the crown. With the Line of Mary Tudor at such a low and a Male King as the Senior line claimant waiting in the wings, Queen Elizabeth I's Minster Sir Robert Cecil worked hard to make James VI king of England.