Instruction:
Classify each of the following as either a great house or minor house in the series "A Song of Ice and Fire": Targaryen, Stark, Tyrell, Martell, Greyjoy, Baratheon, Lannister, Cerwyn, Karstark, Hornwood, Merryweather, Tarly

Response:
Great house: Targaryen, Stark, Tyrell, Martell, Greyjoy, Baratheon, Lannister
Minor house: Cerwyn, Karstark, Hornwood, Merryweather, Tarly