What cowardly prince stole the wife of Menelaus in greek mythology?

He was Paris, a prince of Troy. He was not at all cowardly, eventually killing super-hero Achilles in battle during the Greek attack on Troy. And he didn't steal king Menelaus' wife Helen, she went of with him very willingly, bringing along a lot of the family wealth to make her new life with Paris all the more enjoyable.

When the Trojans offered to give Helen back, the Greeks asked what about the treasure she took. The Trojans said no way, just the woman who was quite expendable, but not the money, so the siege continued.