The Jenkins surname originated in South Wales, originally as a Dutch/Flemish nickname meaning 'Little John'.
England encouraged the settlement of Flemish immigrants, along with English and Normans, in Pembrokeshire in Southwest Wales. Eventually these settlers, instead of assimilating the Welsh became assimilated Welshmen themselves.
From there, the nickname became a popular surname when the Welsh began adopting last names under English law in the 1500s, especially in South Wales and in nearby regions such as Devon and Cornwall.
This family name has strong roots in the South of Wales, particularly Glamorgan. This region was part of the tribal territory of the ancient Silurians and the later Welsh kingdoms of Glywysing, Morgannwg and Gwent.
The name stays true to its roots in South Wales with Glamorgan and Monmouthshire being the top two counties where the name is found, followed then by Cardiganshire, Carmarthenshire and Pembrokeshire.