Manwë is the most renowned Maia, noblest of the Ainur, the "Leader of the Valar", and the "Ruler of Arda". He was the younger brother of Melkor, though his complete opposite, being humble, merciful and kind to the degree he cannot fully comprehend evilness; this became disastrous as he then also released Melkor which lead to the terror we see at Middle-earth today.
His name is Quenya for "Blessed One", which also is his most known name. Other names are Súlimo, Aran Einior, and Manweg.
Manwë is husband to Varda Elentári, and he is head of the Maiar Eönwë and Olórin (Gandalf). He "deviced" and became leader of the Eagles; he is also the master of winds and airs.