Battle of Thargelion (375 Y.S.) - The Battle of Thargelion was Men's first exposure with the armies of Morgoth.  He was determined to prevent an alliance between Men and Elves and tried to destroy the newly arrived race at Thargelion, which means "Land beyond Gelion".

 

"But Morgoth, seeing that by lies and deceits he could not yet wholly estrange Elves and Men, was filled with wrath, and endeavoured to do Men what hurt he could.  Therefore, he sent out an Orc-raid, and passing east it escaped the leaguer, and came in stealth back over Ered Lindon by the passes of the Dwarf-road, and fell upon the Haladin in the southern woods in the land of Caranthir." ~The Silmarillion, chap. 17 (Of the Coming of Men into the West)

 

However, the Elves came to the aid of the Haladin, and an alliance between Elves and Men was established.