Luwin

Luwin is a character in Game of Thrones. He is played by Donald Sumpter and appears in the first episode.

Luwin is a maester, a learned man of science and medicine, and serves House Stark. He is very loyal to the Starks and they value his wise counsel and experience. He has delivered all five of Catelyn's children.

In the books
In the Song of Ice and Fire novels Luwin is a member of the order of maesters, who are trained in the Citadel, a structure in the ancient city of Oldtown on the far south-western coast of Westeros. Luwin has forged several links of his maester's chain, showing areas where he has interest and expertise, such as herblore and astronomy. He is also one of the few maesters to have studied the so-called 'higher mysteries', meaning magic. This study is theoretical, and meant to demonstrate to those who show an interest in it that magic, if it ever existed in the first place, is dead and gone from the world.

Luwin lives in the maester's tower in Winterfell. Amongst his duties is sending and receiving messages carried by ravens.