All of these videos contain spoilers.
Here are a series of character recaps (seasons 1 - 7) from Hollywood Studio and the actors who portrayed them.
Lena Headey about History of Cersei Lannister
Nikolaj Coster Waldau about History of Jaime Lannister
Peter Dinklage about History of Tyrion Lannister
Kit Harington about History of Jon Snow
Sophie Turner about History of Sansa Stark
Maisie Williams about History of Arya Stark
Isaac Hempstead Wright about History of Bran Stark
Emilia Clarke about History of Daenerys Targaryen
John Bradley about History of Samwell Tarly
Liam Cunningham about History of Davos Seaworth