He was getting on in years when Luke Skywalker first met him at Tibannopolis. He could use The Force to detect when Bespin would erupt large amounts of gases.

He agreed to study the Force with Luke on Yavin 4 and became one of the first twelve students at the Praxeum.

He was there during the Exar Kun Crisis. Kun tried to use Streen to kill Luke, but the combined power of the other students destroyed Kun's spirit forever. Streen accomplisehed a numer of things at the Praxeum.

Streen put his powers to use in an attempt to decipher the Books of Massassi, and eventually became a Master himself when Luke went off in search of his mother with Akanah.

When Luke returned Streen stayed, continuing to teach and be a part of the family that he found himself in.