On July 17, 1328, in accordance with the Anglo-Scottish peace treaty of Northampton, the four-year-old David was married to Joanna, sister of King Edward III of England. The boy succeeded his father, Robert I the Bruce, as king of Scots on June 7, 1329. A rival claimant to the Scottish throne, Edward de Balliol, a vassal of Edward III, became de facto king after Edward's victory over Sir Archibald Douglas, regent since 1332, at Halidon Hill, Northumberland (July 19, 1333). In 1334 David went into exile in France, where he was maintained generously by King Philip VI. In 1339 and 1340 he fought in Philip's fruitless campaigns against Edward III. By 1341 he was able to return to Scotland, but he did little as king except to make futile raids into England. During the French siege of English-held Calais he attempted a diversion on behalf of Philip VI but was defeated, wounded, and captured at Neville's Cross, County Durham (Oct. 17, 1346).

Held prisoner by the English, David was released in 1357 in return for a promised ransom that proved to be more than the Scottish government could pay. In 1363 David, now on cordial terms with Edward III, proposed that a son of the English king should succeed to the throne of Scotland in return for the cancellation of the ransom. The arrangement, which made an enemy of his nephew and lawful successor, the future Robert II, was repudiated by the Scottish Parliament. In his last years David inspired further opposition by his financial extravagance.