Blue Wizards (or the Ithryn Luin) are two notoriously mysterious characters of Middle-earth. They are only hinted at in The Lord of the Rings, where Saruman says there are five Wizards. However, other writings of Tolkien have more to say. In a writing found in Unfinished Tales, Tolkien writes that the two Wizards were sent to the East. Their names in Valinor were Alatar and Pallando, and they are Maiar of the Vala Oromë.
In a letter, Tolkien says that the two wizards went into the East, and likely failed their mission, perhaps having started magical cults. However, all of this changes in a text written in the last year or two of Tolkien's life. The names they used in Middle-earth are now given - Morinehtar and Rómestámo (Darkness-slayer and East-helper). They are said to have arrived not in the Third Age, but in the Second, around the year 1600, the time of the Forging of the One Ring. Their mission though is still to the east, to weaken the forces of Sauron. And it is here said that the Wizards far from failed; rather, they had a pivotal role in the victories of the West at the end of both the Second and the Third Ages.
Like most names in Tolkien's works, the names of the Blue Wizards are significant. The name Romestamo means East-helper, coming from the Quenya word romen, meaning uprising, sunrise, east. Here, Rómestámo incorporates not only his relation to the East of Middle-earth, but also his mission there: to encourage uprising and rebellion against Sauron. Similarly, Pallando may include the Quenyan palan meaning far and wide.