From here you can look into two histories: that of Wath Morris, and that of Morris Dancing itself.
Briefly, morris dancing is an ancient dance dating back many centuries whose origins are now unknowable.
Wath Morris are a "relatively" new side, formed in 1973 and first dancing in 1974. They have evolved slowly since their inception and dance two distinct styles of morris: Cotswold (specifically Bledington village) dances and Border Morris, from the English / Welsh borders. They have dabbled in other morris dances, specifically Longsword (Poppleton and Flamborough) and Rapper Dance. Wath Morris are also a mummers side performing now only in the mid-winter months ususally plays collected in South Yorkshire or plays derived from that tradition. Essentially these are either The Derby Tup or St. George plays.
For more details on the history of Mmorris dance, or on the history of Wath Morris, please click below:
The History of Morris Dancing