From PIE *kar- (hard, strong) — the same root behind Greek 'krátos' (power), giving English 'democracy' and every '-cracy.'
Solid, firm, and rigid; not easily broken, bent, or pierced; requiring great effort; difficult to bear or endure; severe or harsh.
From Old English 'heard' (solid, firm, not soft, strenuous, severe), from Proto-Germanic *harduz (hard, strong, bold), from PIE *kort-u- (strong, powerful), from the root *kar- or *krāt- (hard, strong, powerful). The same PIE root produced one of the most important political words in Western civilization: Greek 'kratýs' (strong, mighty, powerful), from which derives 'krátos' (strength, power, rule) — the source of '-cracy' (rule by) in 'democracy' (rule by the people), 'aristocracy' (rule by the best), 'plutocracy' (rule by the wealthy), 'bureaucracy' (rule by the desk), and 'theocracy' (rule by god). The connection between physical hardness and political power runs
English 'hard' and the suffix '-cracy' (as in 'democracy,' 'aristocracy,' 'bureaucracy') descend from the same PIE root *kar- (hard, strong). Greek 'krátos' (power, rule) is a direct descendant, and 'democracy' literally means 'rule by the people-power.' So when you say something is 'hard,' you are using the same ancient root that Greek used to describe political power. The personal name 'Richard' contains this root too — from Germanic