Robert "Sweet Robin" Arryn was the sickly Lord of the Vale during the War of the Five Kings. He was the only son of Jon Arryn and Lysa Arryn nee Tully. He perished near the end of the war and was succeeded by his cousin Harrold Arryn.
Robert was the only son Jon Arryn and Lysa Tully and was afflicted from an early age with illness that caused him to have seizures. Robert became the Lord of the Vale following the death of his father, Jon Arryn. His mother, Lysa Tully, served as the regent of the Vale during the first year of his rule but his later rule was characterized by Lord Petyr Baelish.
Robert died near the end of the War of the Five Kings shortly after his mother. Though Petyr Baelish claimed it to be the illness Robert suffered, rumors circulated the Baelish had a role in Robert's death.