The Longbottom family

You probably read about Harfang Longbottom in chapter one and thought, Oh he must be related to Neville Longbottom! 
He most likely is, though we don't know how. However he is, he is somehow related to Neville's unknown grandfather. 
Mr. Longbottom married Augusta and they had Frank Longbottom. He married Alice, and they later had Neville. Neville married a Hufflepuff witch named Hannah Abbott.

Neville's grandfather had a brother named Algie Longbottom, who married someone named Enid.
Although I wish to tell you more about the Longbottoms there is nothing more there is nothing more to tell.