A natural harbour found in the south of the Bay of Belfalas. Although it was used as a safe anchorage by Númenorian sailors for many centuries in the Second Age, starting around SA 800, it was most likely first colonized around SA 1800 when the Númenorians began establishing permanent colonies on Middle-earth.

In SA 2280 the Havens of Umbar became a major fortress for Númenor against the might of Sauron and his allies. In the year 3261 Sauron surrendered to Ar-Pharazôn at the Havens of Umbar and was brought back to Númenor.

After the Downfall of Númenor the Havens were in the control of the Black Númenorians, allied with Sauron.

In the Third Age, Eärnil I of Gondor took back the Havens of Umbar and made them into a fortress against Sauron's allies.

Umbar remained under the control of Gondor until the Havens were taken by the sons and allies of Castamir in TA 1448. From that time on the people of Umbar became known as the Corsairs of Umbar and became one of Gondor's major enemies.

In TA 1810 the Havens of Umbar were taken back by Gondor's Telumehtar Umbardacil, who drove out the Corsairs, but with the invasion of the Wainriders in TA 1851 control of Umbar was once again relinquished to Gondor's enemies.

In TA 2979 Aragorn, using the alias Thorongil, led a force from Gondor that managed to the destroy almost the entire fleet of the Corsairs.

The threat of the Corsairs finally ended with the destruction of the Ring in TA 3019. Prior to that the fleet of the Corsairs was taken by the Deadmen of Dunharrow, led by Aragorn, while the Corsairs were ravaging Pelargir. Aragorn used the Corsair fleet to sail up the Anduin and join the Battle of the Pelennor Fields.
Encyclopedia entry originally written by PotbellyHairyfoot