Henry VII (January 28, 1457 – April 21, 1509), King of England, Lord of Ireland (August 22, 1485 – April 21, 1509), was the founder of the Tudor dynasty and is generally acknowledged as one of England's most successful kings.
Henry Tudor was the posthumous son of Edmund Tudor, 1st Earl of Richmond, a half-brother of King Henry VI of England. His mother was Margaret Beaufort, a descendant of King Edward III through John of Gaunt and Katherine Swynford. From his father, he inherited the title Earl of Richmond; from his mother, his questionable claim to the throne of England. He was born in Pembroke, Wales, but grew up in exile in Brittany, having fled from the Yorkist kings of England. As an individual with some claim to the throne (even a very weak one), he knew the Yorkist monarchs would want him dead.
After the failure of the revolt of his cousin, Henry Stafford, 2nd Duke of Buckingham, Henry VII became the leading Lancastrian contender for the throne of England. Having gained the support of the in-laws of the late Yorkist King Edward IV, he landed with a force in Wales and marched into England, accompanied by his uncle, Jasper Tudor. Wales had traditionally been a Yorkist stronghold, and Henry owed the support he gathered to his ancestry, being directly descended, through his father, from the Lord Rhys. He amassed an army of around 5000 soldiers and travelled north. There his Lancastrian forces decisively defeated the Yorkists under Richard III at the Battle of Bosworth Field in 1485 when several of Richard's key allies switched sides or deserted the field of battle. This battle effectively ended the long-running Wars of the Roses between the two houses. Henry's claim to the throne was tenuous and based upon a lineage of illegitimate succession. However, this was no barrier to the Throne; inheritance was not the sole method of becoming Sovereign. Claims could also be based on nomination (by the previous Sovereign), statute, prescription (de facto possession of power) and, as was the case with Henry VII, conquest.
The first of Henry's concerns on attaining the monarchy was the question of establishing the strength and supremacy of his rule. There were few other claimants to the throne left alive after the long and bloody civil war, so his main worry was pretenders such as Perkin Warbeck, who were backed by disaffected nobles. Henry succeeded in securing his crown by a number of means but principally by dividing and undermining the power of the nobility.
Henry's first action was to declare himself king as-of the day before the battle, thus ensuring that anyone who had fought against him would, technically, be guilty of treason. It is interesting to note, therefore, that he spared Richard's designated heir, John de la Pole, Earl of Lincoln.
Another method Henry used to secure his throne was to carry out his promise to marry Elizabeth of York, daughter and heir of King Edward IV. The marriage took place on January 18, 1486 at Westminster. This unified the warring houses, and gave him a greater claim to the throne due to Elizabeth's line of descent (though there is evidence that Edward was born illegitimate).