Short answers, pulled from the story.
Edward Seymour, 1st Duke of Somerset, was the eldest surviving brother of Queen Jane Seymour and served as Lord Protector of England from 1547 to 1549. He became the effective ruler of England through a calculated manipulation of King Henry VIII's final days and his sister's marriage to Henry VIII in 1536.
Edward Seymour, 1st Duke of Somerset, was executed for felony on the 22nd of January 1552 after scheming to overthrow John Dudley's regime. His head was cut off upon Tower Hill between eight and nine o'clock in the morning.
Edward Seymour, 1st Duke of Somerset, seized power by securing letters patent in March 1547 that granted him the authority to appoint members to the Privy Council and consult them only when he chose. This move effectively turned the collective governance envisioned by Henry VIII into an autocracy with Seymour ruling largely by proclamation.
Edward Seymour, 1st Duke of Somerset, lost power due to the financial ruin of the crown caused by his military ambitions and the unpopularity of his religious measures and agrarian grievances. These factors resulted in unrest across England and provoked uprisings including the Prayer Book Rebellion and Kett's Rebellion, leading to his fall from power in October 1549.
Edward Seymour, 1st Duke of Somerset, brother Thomas was eventually beheaded in March 1549 after attempting to seize the governorship of the king's person. Thomas had protested his exclusion from power and no previous Lord Protector had ever held that role.
John Dudley, Earl of Warwick, emerged as the leader of the Council and effectively succeeded Edward Seymour, 1st Duke of Somerset, in February 1550. Dudley had previously been Earl of Warwick and moved decisively against Somerset during a meeting at Ely Palace.