During his military service, the outcome of the Sarmatian wars strongly affects him due to the appalling bloodshed and atrocities committed. He also begins to question the value of Trajan's policy of military expansion. Trajan, in old age, begins an unsuccessful military campaign in Parthia after his successes over Dacia and Sarmatia. After a major defeat, Trajan hastily names Hadrian as his successor in a will shortly before his death. Following the death of Trajan, he hesitantly has his rivals executed and makes peace with Parthia. He travels frequently throughout the provinces of the Roman Empire while undertaking numerous economic and military reforms, promoting in his words: “humanitas, libertas, felicitas.” During a visit to Britain, he describes the construction of Hadrian's Wall, which represents part of his vision of curbing the military expansion of his predecessor and promoting peace.