Crispus vs Wei Yan

Constantine appointed Crispus as Caesar, making him the heir apparent to the Western provinces. Crispus was given command of the Gallic frontier and later played a key role in the war against Licinius. His appointment was part of Constantine's dynastic planning.

Crispus led a Roman army to victory against the Frankish tribes along the Rhine frontier. The campaign secured the border and demonstrated his military competence. Constantine praised his son's success, and Crispus was hailed as a capable general.

Crispus commanded the Roman fleet in the Battle of the Hellespont against Licinius's navy. His victory destroyed Licinius's naval forces and allowed Constantine to cross into Asia Minor. This was a decisive moment in the civil war that ended the Tetrarchy.

Crispus was executed at Pola on the orders of his father Constantine, under unclear circumstances. The reasons remain debated, possibly involving accusations of adultery with his stepmother Fausta. His death was a major scandal in the Constantinian dynasty and led to the later execution of Fausta.

After Liu Bei conquered Hanzhong, he appointed Wei Yan as the governor of this strategic region, bypassing the more senior Zhang Fei. Wei Yan successfully defended Hanzhong against Wei attacks for years, proving his competence.

Wei Yan served as a frontline commander in Zhuge Liang's Northern Expeditions against Wei. He proposed the risky 'Ziwu Valley' plan to attack Chang'an directly, but Zhuge Liang rejected it. Wei Yan's forces achieved several tactical victories.

After Zhuge Liang's death, Wei Yan clashed with the chief of staff Yang Yi over command. Wei Yan burned the retreat route and was accused of rebellion. He was defeated, captured, and executed by Ma Dai. The historical accuracy of his 'rebellion' is debated.