Heraclius' inability to rule the Empire as his death neared did Byzantium no favors.
After Heraclius' death in 641, the former Empress Martina declared herself, her son, Heracleonas, and her stepson, Constantine, co-emperors of the Byzantine Empire.
However, the citizens of Constantinople refused to accept this.
And so, when Constantine III died sometime between May 24 and May 26, 641 (considered by the majority of the Byzantines to have been done by Martina's hand), Heracleonas and his mother were deposed the following summer.
Heraclonas' nose was slit and Martina's tongue was wrenched out.
These acts ensured that Heraclonas could never become Basileus (Emperor) – the physical deformation would have made it impossible.
However, as suspects of committing regicide, their exile to the island of Rhodes was a light punishment.

With Constantine dead, the populace of Constantinople turned to his 11-year-old son (also known as Heraclius) who was crowned as the Byzantine Emperor, and changed his name to Constans, thus becoming Constans II.
Heraclius' inability to rule the Empire as his death neared did Byzantium no favors. After Heraclius' death in 641, the former Empress Martina declared herself, her son, Heracleonas, and her stepson, Constantine, co-emperors of the Byzantine Empire. However, the citizens of Constantinople refused to accept this. And so, when Constantine III died sometime between May 24 and May 26, 641 (considered by the majority of the Byzantines to have been done by Martina's hand), Heracleonas and his mother were deposed the following summer. Heraclonas' nose was slit and Martina's tongue was wrenched out. These acts ensured that Heraclonas could never become Basileus (Emperor) – the physical deformation would have made it impossible. However, as suspects of committing regicide, their exile to the island of Rhodes was a light punishment.
With Constantine dead, the populace of Constantinople turned to his 11-year-old son (also known as Heraclius) who was crowned as the Byzantine Emperor, and changed his name to Constans, thus becoming Constans II.
Byzantine Empire under the Heraclian dynasty