Many names used in
George R. R.
Martin's A Song of Ice and Fire (Game of Thrones) are elaborations or new spellings of common English medieval names:
Eddard -
EdwardJon -
JohnRobb -
RobertCatelyn -
CatherineRickon -
Rick,
RichardJoffrey -
GeoffreyJaime -
Jamie,
JamesMargaery -
MargeryTommen -
ThomasMelisandre -
MelisandeLancel -
Lancelot
Sansa was surely inspired by
Sancha / Sancia, which was a common name among European royalty during the Middle Ages.