 In the first half of the 17th century a rising cost of consumable goods and a series of bad harvests brought about economic changes in Glamorgan . Those with enough wealth were able to seize on opportunities created by these unsettled conditions and set about enlarging and enclosing farm lands . The enclosure of freehold lands that began in the later Middle Ages now gained momentum and farms that were once owned by individual farmers were now owned by small groups of wealthy landowners . By the 19th century most of the Rhondda farms and estates were owned by absentee landlords , such as the Marquis of Bute , Earl of Dunraven , Crawshay Bailey of Merthyr and the De Winton family of Brecon . 
