Caernarfon Castle looks impregnable… but a chain is only a strong as its weakest link …and in the case of Caernarfon it was the town walls …and that the castle walls facing into the town had not been finished when …in the autumn of 1294 Madog ap Llywelyn attacked.
The Annales of Nicholas Trevet tell us that “villam et castrum de Karnervan combusserunt” that both town and castle are burned. But he also goes on to say that “magna Anglicorum multitudine”, that is, “a great multitude of the English” who “qui nihil tale suspicantes ad nundinas venerant, interfecta” or “without suspicion had come to the market and were slain within.”

Sheriff, Roger de Pulesdon, had also been murdered, reputedly hung from the eaves of his own house, some said it was more a savage lynching. (If you want irony btw his descendant would be a supporter of Owain Glyndwr).
The East Gate of the town walls …bottom of the upper picture…contained the Exchequer and was burned, together with its records. ….which is one of the reasons we have fewer building records for Caernarfon than for Conwy.
We know the extent of the castle wall facing the town, and that it was incomplete, from a letter dated 25th February 1296 … a year after the attack …Master Walter was taking over from Master James the repair and finishing job at Caernarfon as James began work in Beaumaris…this is what Master Walter wrote …
“Memorandum quod in muro inchoato circa motam castri de Carnaruan sunt iiij turres inchoate qui quidem murus continet in longitudine xviij perticatas; et de istis perticatis viij perticate continent in altitudine xij pedes, et x perticate continent in altitudine xxiiij pedes; et iste murus continet in spissitudine xv pedes.”
“You should note that there are on the unfinished wall about the moat / ditch of the castle of Caernarfon, there are 4 unfinished towers that are contained in the lengthwise wall of 18 perche (99 yards); of which wall there are 8 perches (44 yards) contained in height-wise 12 feet, and 10 perche (55 yards) is contained in height-wise 24 feet; and these walls contained in thickness 15 feet.”
Caernarfon looks peaceful now … but this was no fairytale …and for the people of Caernarfon market slaughtered in the autumn of 1294 there was no happy ending.