Some historians believe that at an unknown time in the decade 899 to 909, Æthelred's health collapsed and Æthelflæd became the effective ruler of Mercia. Cyril Hart and Maggie Bailey believe that it occurred by 902. Bailey cites "Mercian Register" entries from 902 showing Æthelflæd acting alone or in conjunction with Edward in military operations. Irish annals called the "Three Fragments" also suggest that Æthelred was unable to take an active part in government from about 902, although he did attend a meeting in 903 with King Edward, Æthelflæd and Ælfwynn. In 1998 Keynes suggested that Æthelred may have been incapacitated by illness at the end of his life, but in a summary of his career in 2014 Keynes does not mention this, stating that Æthelred and Æthelflæd cooperated with King Edward in campaigns against the Vikings. Martin Ryan also makes no mention of a decline in Æthelred's health, describing him as joining Edward in encouraging thegns to purchase land in Viking territories. In Michael Livingston's view, he campaigned with Edward in Northumbria in 909, and may have died as a result of wounds sustained at the Battle of Tettenhall in 910.