Battle of the Gladden Fields:

The battle of the Gladden Fields was fought between orcs, guarding the area from retreating Dúnedain after the War of the Last Alliance and Isildur, with a small guard. Isildur was heading north towards the passes of the Misty Mountains and Rivendell. He was ambushed with a small guard. They managed to survive the day, but that evening, Isildur, wearing the Ring, attempted to swim the Anduin. The Ring slipped off his finger and he was seen by the orcs. He was shot by their arrows and killed. However, as was later found, the area where they were was not very deep, about shoulder deep on a tall man, and fairly slow-running.
There are at least two different traditions recorded about the Battle of the Gladden Fields, with the other stating that they were surrounded by a great host of orcs and overthrown. I believe the first tradition, as it was borne out by fact, as they found some artifacts of Isildur's death in Orthanc after. Only three men made it to Rivendell, including Ohtar, with the shards of the Narsil.