From the longer Wikipedia page [1]
Edmund de la Pole, 3rd Duke of Suffolk, 6th Earl of Suffolk, KG (1471/1472 – 30 April 1513), Duke of Suffolk, was a son of John de la Pole, 2nd Duke of Suffolk and his wife Elizabeth of York.
His mother was the second surviving daughter of Richard Plantagenet, 3rd Duke of York and Cecily Neville. She was also a younger sister to Edward IV of England and Edmund, Earl of Rutland as well as an older sister to Margaret of York, George Plantagenet, 1st Duke of Clarence and Richard III of England.
His eldest brother John de la Pole, Earl of Lincoln (c. 1464-1487), was heir-apparent to his maternal uncle, Richard III of England, ("Henry VII and the English nobility", T.B. Pugh, The Tudor nobility, ed. G.W.. Bernard, (Manchester University Press, 1992)), who gave him a pension and the reversion of the estates of Lady Margaret Beaufort, Countess of Richmond and Derby. However, on the accession of Henry VII following the Battle of Bosworth Field, Lincoln took the oath of allegiance instead of claiming the throne for himself. In 1487, Lincoln joined the rebellion of Lambert Simnel and was killed at the Battle of Stoke.
After the death of his older brother, Edmund became the leading Yorkist claimant to the throne. Nevertheless, he succeeded to the title Duke of Suffolk in 1491, though in 1493 Edmund's title was demoted to the rank of Earl. He married Margaret, daughter of Sir Richard Scrope.
In 1501 the headstrong Edmund fled England with the help of Sir James Tyrrell, who was subsequently executed for these actions.
Edmund sought the help of Maximilian I, the Holy Roman Emperor. In 1502 Maximillian agreed to a treaty not to back de la Pole should he make an attempt on the throne of England. In 1506, Maximilian's son, (Philip I of Spain), was blown off course while sailing, and reluctantly and unexpectedly became a guest of Henry VII. Needing to set sail again in order to claim his wife's inheritance (Castile), he was persuaded by Henry to hand over the Earl of Suffolk. Henry agreed to the proviso that Suffolk would not be harmed and restricted himself to imprisoning the Earl. The next king, Henry VIII, did not feel bound to this agreement and had Suffolk executed in 1513.