In 613, when the first wife of Heraclius, Eudocia, died he married Martina, but this marriage was never approved of by either the people of Constantinople or the Church. Despite his disapproval and attempts to convince Heraclius to repudiate Martina, Patriarch Sergius I of Constantinople performed the ceremony himself and crowned Martina in the Augustaeum after she was proclaimed Augusta by Heraclius. Even the members of the imperial family voiced their objections, with Heraclius' brother (and Martina's uncle) Theodore continually criticising Heraclius because of this relationship.
However, the Emperor and the Empress were clearly a very close couple: Martina accompanied her husband in his most difficult campaigns against the Persians. 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.
They had at least ten children, of whom at least two were handicapped, which was seen as divine punishment for the incestous marriage. Among them was Heraclius II, called Heracleonas, who through his mother’s influence received the title of Augustus on July 4, 638.
On his deathbed in 641 Heraclius left the empire to both his son from the first marriage, Heraclius Constantine (as Constantine III) and Heracleonas (as Heraclius II), granting them with equal rank. Martina was to be honoured as empress and mother of both of them.
Relations of Martina and her step-son were always difficult. When Constantine III died suddenly of tuberculosis only four months later, the common belief was that the Empress poisoned him to leave Heraclonas as sole ruler. Also Martina began immediately to exile the prominent supporters of Constantine and with the help of Patriarch Pyrrhus I of Constantinople, one of her primary advisors, revived the policy of Monotheletism.
Her actions and the rumors of poisoning Constantine III caused the people and the Senate to turn against Martina and her son. The Armenian Valentine Arsacidus (Arshakouni) with the troops from Asia Minor, marched to Chalcedon and a frightened Heracleonas named Constans II, son of late Constantine III, a co-emperor.
This, however, failed to ease the discontent and by the end of the month the Byzantine Senate deposed him. His nose was slit, Martina's tongue cut out and they were exiled to Rhodes. Constans II became sole emperor.