3. =Troubles in Scotland. 1329--1336.=--On his return, Edward looked in another direction. In =1329= Robert Bruce died, leaving his crown to his son, David II., a child five years old. Certain English noblemen had in the late treaty (see p. 231) been promised restoration of the estates of their ancestors in Scotland, and in =1332= some of them, finding the promise unfulfilled, offered English forces to John Balliol's son, Edward, to help him to the Scottish crown. Aided by his English allies, Edward Balliol landed in Scotland, defeated the Scottish army at Dupplin, and was crowned king. Before the end of the year he was surprised at Annan, and fled to England to appeal to Edward for help. Though Edward had all the love of enterprise of his grandfather, Edward I., yet there was a marked contrast between the deliberate calculation of Edward I. and the almost accidental way in which Edward III. involved himself in an attempt to regain the lordship of Scotland. In =1333= he laid siege to Berwick, then in the hands of the Scots. The Scots advanced into England, and their spearmen crossed a marsh to attack the English array of knights and archers posted on the slope of Halidon Hill. The arrows poured like rain on their struggling columns. The Scots were thrown into confusion, and their whole army was almost destroyed. Berwick was regained, and Bannockburn, it seemed, was avenged. Edward not only set up Balliol as his vassal, but compelled him to yield all Scotland south of the Forth to be annexed to England. Such a settlement could not last. Balliol was as weak as his father had been, and the Scots, recovering courage, drove him out in =1334=. Edward invaded Scotland again and again. As long as he was in the country he was strong enough to keep his puppet on the throne, but whenever he returned to England David Bruce's supporters regained strength. The struggle promised to be lengthy unless help came to the Scots.