John Balliol, King of Scotland, was born around 1249CE son of an English nobleman, John 5th Baron of Balliol (Bailleul in France). His connection to Scotland came through his mother, Devorguilla, daughter of Alan, Lord of Galloway, and descendant, at some remove, of David I of Scotland. He was, however, married, by the 1280s to Isobel de Warenne, daughter of John, the English Earl of Surrey, and was therefore Scots only by birth, not by nurture or marriage.
The death, in 1286, of Alexander III and, four years later, of Alexander's daughter Margaret, Maid of Norway, aged 7 and on her way to Scotland to be crowned Queen, placed John within the circle of hopefuls, none of them with unblemished claims, who hoped to be Scotland's next king. It was decided that the contest for the crown would be fought in the courts rather than on the battlefield, and, by one means or another, Edward I of England achieved selection as final arbiter. He arrived in Scotland together with a large army and, finding the two strongest candidates were Balliol, and Robert Bruce of Annandale, Edward assessed them on the basis of his underlying motive: to make Scotland a feudal dependency of England forever. Finding Balliol more amenable to swearing fealty (probably because he had always lived with Englishmen as his kings), Edward declared Balliol the rightful king, and took his oaths of loyalty and obedience, treating these as acknowledging the submission of Scotland to England forever.
The Bruces (along with many others) could see what this meant: the elder Robert Bruce passed his throne-claim on to his son, and then refused to swear homage to Balliol. But, because there was no violence offered, "King John" could not take any effective action against them. Indeed, he had to suffer the ignominy of being called "Toom Tabard" or "Empty Jacket", in acknowledgment of the fact that he was merely Edward's puppet ruler, with no authority of his own.
Finally in April 1296 Balliol renounced his fealty to Edward, who immediately marched north with his army, crushed the Scots, captured key castles, and finally captured Balliol himself. In July 1296 he was forced to surrender himself and the entire kingdom ot Edward, who had the Stone of Destiny, upon which Scots kings were crowned, removed to Westminster. Stripped of his regalia, Balliol was shipped south, first to Hereford and then to the Tower of London, where he remained until 1299, when he was released to his French estates, to die in 1313. His son, Edward, was to be thrust onto the throne of Scotland at various times between 1332 and 1356, always as an English puppet, but was never recognised by any Scots authority.
In the aftermath of Balliol's surrender of Scotland, Edward I sent English officials north to rule for him, but they met with little sympathy. William Wallace raised an armed revolt, between 1297 and 1305. After his death, Robert the Bruce (grandson of the Robert who had claimed the throne after Margaret's death) was crowned king of Sctoand, and proceeded to drive the English back.
As a footnote, John and Isabella had 2 daughters and a further son. Their son died fighting for England against the Scots, and one of their daughters married a FitzAlan, lord of Bedale, from whom descended a daughter Agnes who married Sir Gilbert Stapleton. He was later to become notorious for participation in the murder of Piers Gaveston, Earl of Cornwall (and close companion of Edward II) in 1312.