The law of effect principle, which states that rewarded behavior is likely to recur, was developed by Edward Thorndike. He suggested that responses followed by satisfaction were bound to happen again.

he is rewarded by his death which he was meant to be rewarded by early retirement

He was rewarded and ended up as a constellation.

Both were rewarded with large plots of land.

Rewarded is the past tense of the verb "reward". Because reward is a regular verb, rewarded is also the past participle.