Lorimer

Lorimer is a character mentioned in the fifth season episode "High Sparrow". He was a knight for whom Podrick Payne squired prior to entering into the service of Tyrion Lannister.

Background
Ser Lorimer was a lesser knight fighting for House Lannister during the War of the Five Kings, with Podrick Payne, member of a lesser branch of House Payne, serving as his squire. One night Lorimer got drunk and stole a ham, which he shared with Podrick. Lorimer was caught and the two were sentenced to be hanged. Lorimer was thus executed, while Podrick was pardoned by Lord Tywin Lannister because of his family name.

Season 5
Podrick tells his history with Lorimer to Brienne.

In the books
In the A Song of Ice and Fire novels, Lorimer's story is quite similar. He's nicknamed "Lorimer the Belly" for being fat. He was a hedge knight serving Lord Leo Lefford. Podrick attached himself to him after his previous master, his kinsman Ser Cedric Payne, died fighting in the Riverlands. Lorimer was hanged as a thief after being found to have stolen a ham.