Also I loved this little discovery, from 1300:

> "Þe euele man louȝ, whan that he sawe my peine, and it was a crueel louȝter, wiþouten merci or pitee as of a man þat haþ no rewþe in his herte."

"The evil man laughed, when he saw my pain, and it was a cruel laughter, without mercy or pity as of a man that has no rewthe in his heart."

In other words, a rewthe-less man.

We've retained the word "ruthless" but no longer use the word "ruth", "a feeling of pity, distress, or grief."