Probably the oldest manuscript to attach "Mawr" to Rhodri was Peniarth Ms 17, of...

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Probably the oldest manuscript to attach "Mawr" to Rhodri was Peniarth Ms 17, often called The History of Gruffudd ap Cynan, believed to date from the mid-1200's. The pedigrees contained in a 10th century manuscript, Harleian 3859, simply call him Rhodri. Darrell Wolcott, Ancient Wales Studies. Wikipedia's Lame Biography of Rhodri Mawr Accessed February 17, 2017 jhd

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