Complex sentence: The name changed to Llanfihangel Genau'r Glyn in the 16th century, then in the 19th century this changed to the meaningless name Llandre, but the old name of Llanfihangel Genau'r Glyn still occurs frequently in books of Welsh history.
Split into simpler sentences: The name changed to Llanfihangel Genau'r Glyn in the 16th century. C.C.Green, "Coast Lines of the Cambrian Railways Volume One" (Wild Swan Publications, 1993) The old name of Llanfihangel Genau'r Glyn still occurs frequently in books of Welsh history.