Succeeded - and then failed.
Plague and his own infertility were just two problems lying in wait for the boy. But things initially looked promising. He was his country's first anointed king - literally. The Pope had given his father some holy water to sprinkle on his son at his coronation. Alas, being the "Lord's anointed" did not protect David from rogues, rivals and his own stupidity.
One rival was his brother-in-law Edward III of England. Edward, who was pretty good at running a country, connived at the defeat of his relation at the battle of Halidon Hill in 1333. The nine-year-old king was sent into exile in France for eight years.
Five years after his return, David, now a not-so mature 22-year-old, decided to invade England. Why? To help his ally King Phillip of France. A wise move? No. The lad, though brave, was not a warrior king like his father.
Crossing the border into Northumberland, he fought and lost the battle of Neville's Cross. Found hiding under at bridge at Aldin Grange, he was captured and sent off again - this time for 11 years in an English jail.
Once there, as is the fate of many prisoners, David became close to his captors - principally Edward. The childless monarch is thought to have wanted his brother-in-law to take over the Scottish throne on his death.
This did not go down well in Scotland. Nor did the enormous ransom that eventually secured David's release. Hostages were handed over to ensure that the bill - pound;100,000 in 10 instalments - was paid in full.
Taxation was increased and people resented the payments. When David died suddenly at the age of 46, his nephew, whom he disliked, inherited the crown. It was the end of the Bruce line and many Scots might well have thanked the lord for ridding them of his anointed.