By 1403 only a handful of castles, including Harlech, still stood against the rebels, but the castle was under-equipped and under-staffed to withstand a siege, the garrison having just three shields, eight helmets, six lances, ten pairs of gloves, and four guns.
I 1403 var kun en håndfuld borge, inklusive Harlech, fortsat under engelsk kontrol, men borgen havde hverken udstyr eller bemanding til at modstå en belejring, idet garnisonen kun havde tre skjolder, otte hjelme, seks lanser ti par handsker og fire hagebøsser.