How border conflict escalated into Edward I's conquest of Wales

Why did Edward I's relations with Wales turn into conquest?

The conquest is presented as an escalation from unstable border politics and repeated raids into punitive war and permanent occupation.

Edward I was initially willing to leave Wales outside direct English rule while cooperative Welsh leaders stabilised the frontier. After those figures died, renewed raiding and political friction pushed the crown toward punitive expeditions. The conquest is presented as an escalation in which a raid became occupation once Edward chose to stay. The explanation gives the coming castle discussion its political context: fortifications followed a conflict that hardened from border management into permanent control.