Claverse prepares for battle at Loudon Hill. His cornet would avoid battle; the enemy are too worthy to attack. Claverse calls him a coward and leads the attack himself, but his forces are defeated and chased from the field
The "Claverse" of Child's text is, of course, Claverhouse (James Graham of Claverhouse, First Viscount Dundee, c. 1649-1689, known as "Bonnie Dundee" and killed at Killiecrankie; see the entry on "Killy Kranky" for details of that battle).
Drumclog was not, in terms of size, much of a battle (historians have been known to call it "the 'battle' of Drumclog," because the forces were so small). After the restoration, Charles II had appointed James Sharp as Archbishop of Saint Andrews. Bishops were anathema to Presbyterians anyway, and Sharp was unusually obnoxious in his persecutions. He was ambushed and killed on May 3, 1679.
It wasn't really a rebellion, but Claverhouse treated it as if it were, and rode against the "rebels." They were only a few hundred ill-armed men, but Claverhouse had only a handful of troops, who eventually fled.
The success of the Covenanters at Drumclog did not last long; indeed, it helped induce their next defeat. The victory caused many more men to flow to the cause, but they were utterly disorganized. This rabble was defeated at Bothwell Bridge in the same year (see Child 206, "Bothwell Bridge")
There were actually two battles known as Loudon (Loudun) Hill. The first was fought in 1307 between the forces of England and of Robert the Bruce. Magnus Magnusson's_Scotland: The Story of a Nation_ (Atlantic Monthly Press, 2000), pp. 172-173, describes how the Earl of Pembroke challenged Bruce to come out and fight. Bruce did so -- but arranged the battle so that Pembroke's forces charged over a series of hidden trenches. The horsemen went down, and were slaughtered by the Scottish spearmen, with Pembroke fleeing with the rearguard. It was the first real success of Bruce's rebellion (though it probably would not have been enough had not the English King Edward I, "The Hammer of the Scots," died soon after.) It will be obvious that this song refers to the second Battle of Loudon Hill, usually called "Drumclog" to prevent confusion. - RBW