The emperor and the empress were, however, clearly a close couple: Martina accompanied her husband in his most difficult campaigns against the Sassanid Empire. She was also at his side at Antioch when the news was received of the serious defeat by the Arabs at the river Yarmuk in August 636. These defeats would haunt Martina through her regency and make her increasingly unpopular. Her unpopularity with the people of Constantinople may have possibly led to her removal from coinage in 629. However, other scholars advise caution against such view, as her disappearance in coinage came at the same time as Heraclius' major monetary reform.