Grand Maester Ronnel Arryn is the head of the Maesters and Grand Maester of the Realm and the younger brother to Lord Jasper of the Vale, and the head of the Arryn family.
Ronnel was born in late 310 AC to Harrold Arryn and Claryse Arryn, the Lord and Lady of the Vale. Ronnel and his elder siblings knew little of their father for he died of sudden illness in 311 AC, though this was later revealed to be poison. Ronnel and his siblings grew solely under their mother who was now Lady Regent. As such, Ronnel and his siblings took on the more courtly attitude of their mother rather than the knightly attitude of their father.
When Ronnel matured, shortly after the marriage of his brother to Gwyndelyn Hightower, Ronnel journeyed to Oldtown with the Hightowers and there Ronnel began his studies at the Citadel. Ronnel got so far as forging chains when he reached a point where he could no longer continue in the order. Ronnel was married to Marsei Waynwood. The marriage was unfortunately shortlived as she died in childbirth. Ronnel's daughter Theona would survive but in his grief Ronnel ran off, returning to Oldtown where he took th oaths of Maesterhood. His estrangment from the rest of the Arryn family would cause tension between Ronnel and particualrly his brother who had been serving as the Hand of the Queen. Ronnel managed to rise through the ranks of the order and eventually became an Archmaester of the order. Ronnel's growing friendship with the Hightowers helped him return to his family's good grace when Jasper visited his wife's family in Oldtown during Ronnel's tenure as the Citadel's Seneschal. In 357 after the death of Grand Maester Samwell, Ronnel was appointed as the new Grand Maester gaining a seat upon the Small Council alongside his brother.