Simplify the following text for a Grade 15 native English-speaking person.
Original: William Camden wrote that the Normans were first called bigots , when their Duke Rollo , who when receiving Gisla , daughter of King Charles , in marriage , and with her the investiture of the dukedom , refused to kiss the king 's foot in token of subjection - unless the king would hold it out for that specific purpose .
Simplified: William Camden wrote that the Normans were first called bigots , when their Duke Rollo , who receiving Gisla , daughter of King Charles , in marriage , and with her the investiture of the dukedom , refused to kiss the king 's foot in token of subjection , unless the king would hold it out for that purpose .