Irish rebels into the glen - a dense valley bisected by a four-mile-long river with steep sides and covered in dense foliage, rising in places as high as 2,000 feet. The English fought an advancing skirmish with the Irish as they were drawn deeper and deeper into the glen, whose terrain by now had become horrendous, marked by rocks, bogs, and wood. In an effort to gain higher and more defensible ground, or possibly believing his troops had become vulnerable to an ambush, Colonel Moore advanced his troops up the northern slope of the glen. While climbing the steep slopes of the valley, the inexperienced English soldiers were ambushed by the Irish who hid in the woods. The English were sniped at for a long period of time before their discipline collapsed and they turned and fled down the valley. It was at this point that most of their casualties occurred, as the Irish left their cover and fell upon the English with swords, spears, and axes. Dozens of English soldiers were cut down by the pursuing Irish as they tried to escape the field. The remaining English had to fight a rearguard action for several miles until they reached the town of Rathdrum. Only the presence of Grey's cavalry and his rearguard prevented the total annihilation of the English forces. Aftermath Irish sources state that around 800 English soldiers were killed, though the English put their losses at six officers and twenty-five soldiers dead. While it is certainly possible that the English sources had ignored to include the casualties of their Irish allies, the total number of dead is unlikely to have exceeded 100. Among those killed was Peter Carew, cousin of his namesake colonist who had made claims to, and won, large tracts of land in southern Ireland. The remainder of the English force retreated to lowland Wicklow and from there to Dublin. However, the following year, when offered terms, most of the Irish soldiers, including O'Byrne, came in and surrendered. The exception was Baltinglass, who fled for France. In popular culture The battle is commemorated in the folk song "Follow me up to Carlow". See also Irish battles History of Ireland References Bibliography Richard Bagwell, Ireland under the Tudors 3 vols. (London, 1885–1890). John O'Donovan (editor), Annals of Ireland by the Four Masters (1851). Calendar of State Papers: Carew MSS. i., ii., (6 vols., 1867–1873). Nicholas Canny