Beren - The first great hero of Men of Middle Earth, of the House of Bëor.  He would also upset the balance of races by falling in love with the immortal Elf, Lúthien Tinúviel.

"...and the Orcs coming in the still hours before dawn surprised the Men of Dorthonion and slew them all, save one.  For Beren son of Barahir had been sent by his father on a perilous errand to spy upon the ways of the Enemy and he was far afield when the lair was taken...First therefore he pursued the Orcs that had slain his father and his kinsmen, and he found their camp by night at Rivil's Well above the Fen of Serech, and because of his woodcraft he came near to their fire unseen.  There their captain made boast of his deeds, and he held up the hand of Barahir that he had cut off as a token for Sauron that their mission was fulfilled; and the ring of Felagund was on that hand.  Then Beren sprang from behind a rock, and slew the captain, and taking the hand and the ring he escaped, being defended by fate..." ~The Silmarillion, chap. 19 (Of Beren and Lúthien)