The uncle of King Henry VII of England and the architect of his successful conquest of England and Wales in 1485.

Jasper was the second son of Owen Tudor and the former Queen Catherine of Valois, widow of King Henry V. Hence he was a half-brother to King Henry VI, who, on attaining his majority, made Jasper Earl of Pembroke (sometime in 1452 or 1453). Through his father, Owen Tudor, he was a direct descendant of Ednyfed Fychan, Llywelyn the Great's renowned Chancellor; this added greatly to his status in Wales.

His elder brother Edmund was born at Much Hadham Palace in Hertfordshire around 1430. Jasper the second son was born at Bishop of Ely’s manor at Hatfield in Hertfordshire around 1431. There seemed to be a third son, Jasper's younger brother referred to as either Edward, Thomas or most likely Owen Tudor. Owen was born at Westminster Abbey in 1432, when the Dowager Queen was visiting her son Henry VI, her water broke prematurely and she was forced to seek the help of the monks at Westminster Abbey. Owen was taken from her and raised by the monks and according to his nephew Henry VII's personal historian Vergil the child was raised as a monk by the name Edward Bridgewater where he lived until his death in 1502. There is mention of a daughter who became a nun by Vergil but nothing is known of her. Jasper's mother's last child would be born in 1437 mere days before Katherine's own untimely death.

In 1436 when Jasper was about five years of age his mother Catherine of Valois once again was expecting another child, however she realised that she was dying from an illness probably cancer and sought the help of Bermondsey Abbey to be nursed by the sisters there. By 1 January she had written a will and had given birth to a short lived daughter possibly named Margaret. On the 3rd January she died. After her death her husband Owen was arrested. It seems likely that while Katherine had been alive, the regency of Henry VI were reluctant to arrest Owen while the Queen could still protect him. The regents had made it illegal for anyone to marry the widowed queen without their permission, and since Owen was below her in rank, there had been no hope permission would be granted. Owen was sent to Newgate prison, making his way to Wales. Owen's children Edmund and Jasper, and possibly their unknown sister, were given to Katherine de la Pole who was a nun at Barking Abbey in Essex. She was the sister of William de la Pole, 1st Duke of Suffolk, a great favorite of Henry VI. Katherine de la Pole was to provide Owen Tudor's children with food, clothing, and lodging, and both boys were allowed servants to wait upon them as the King’s half-brothers.

Owen Tudor was released from prison, most likely thanks to his stepson Henry VI, and after providing for his stepfather, he also provided for his half-brothers who had become very dear to him. It is not clear whether Henry VI had known the existence of his half-brothers until his mother told him while she was dying in Bermondsey Abbey. After her death, Henry would take care of them and eventually raise them to the peerage. In turn they gave him unwavering loyalty and fought and promoted his and his Lancastrian family’s interests to the best of their ability. Sometime after March 1442, the young Jasper and his elder brother were brought from Barking Abbey to live at court. Henry arranged for the best priest to educate them not just in their academic studies, but on how to live a moral life. Most likely they also received military training, as when they grew up they were given military positions.

Although there was uncertainty as to whether Jasper and his two (or three) siblings were legitimate, their parents' probably secret marriage not being recognised by the authorities, he enjoyed all the privileges appropriate to his birth until 1461, when he was subject to an attainder for supporting King Henry VI against the Yorkists, who eventually deposed him. To his brother the King, Jasper was a tower of strength who strove to place his half-nephew Prince Edward of Lancaster on the throne and provided absolute loyalty to his royal half-brother and the King's wife Margaret of Anjou. Jasper would also help his other sister-in-law Lady Margaret Beaufort raise her son Henry Tudor to the throne in 1485 and he is subsequently known as King Henry VII father of King Henry the VIII.

Wars of the Roses
Jasper was an adventurer whose military expertise, some of it gained in the early stages of the Wars of the Roses, was considerable. He remained in touch with Margaret of Anjou, Queen of Henry VI, as she struggled to regain her son's inheritance, and he held Denbigh Castle for the House of Lancaster. He also brought up his nephew, Henry Tudor, whose father had died before his birth, until 1461, when custody was taken over by William Herbert. Following the return of the Yorkist king Edward IV from temporary exile in 1471, Jasper took the teenage Henry with him into exile, this time in Brittany. It was thanks to him that Henry acquired the tactical awareness that made it possible to defeat the far more experienced Richard III at the Battle of Bosworth Field. On Henry's accession in 1485, Jasper was restored to all his former titles, including Knight of the Garter. He was made Duke of Bedford. In 1488, he took possession of Cardiff Castle.

Marriage and children
Jasper was married on 7 November 1485 to Catherine Woodville (c. 1458 – 1509).
Catherine was the daughter of Richard Woodville, 1st Earl Rivers and Jacquetta of Luxembourg, and thus was sister to (among others) Edward IV's queen Elizabeth Woodville, Anthony Woodville, 2nd Earl Rivers and Richard Woodville, 3rd Earl Rivers. She was also the widow of Henry Stafford, 2nd Duke of Buckingham.
They may have had one stillborn son c. 1490. Catherine survived Jasper and later married Sir Richard Wingfield of Kimbolton Castle.