Thekla, sister of Michael III

Amorian or Phrygian dynasty
Chronology
Michael II		820–829
with Theophilos as co-emperor, 822–829
Theophilos		829–842
with Constantine (c. 833–835) and Michael III (840–842) as co-emperors
Michael III		842–867
under Theodora and Theoktistos as regents, 842–855, and with Basil I the Macedonian as co-emperor 866–867
Succession
Preceded by Leo V and the Nikephorian dynasty		Followed by Macedonian dynasty

Thekla (Greek: Θέκλα; around 822/23 – after 867, Constantinople) was a princess of the Amorian dynasty of the Byzantine Empire.

She was probably the eldest daughter of emperor Theophilos and Theodora. She had four sisters (Anna, Anastasia, Pulcheria, Maria) and two brothers, Constantine and Michael III.

On Theophilos' death in 842, she joined her mother as a co-empress (Augusta) and appeared as such on coins with her younger brother. However, government was really in the hands of the eunuch Theoktistos. There are different accounts of Thekla's fate after her mother's fall in late 855 or early 856, but in 858 Thekla and her sisters Anna, Anastasia and Pulcheria (Maria had already died in 840) seem to have entered a nunnery in Constantinople. Thekla is said to have been living there at the time of her brother's murder by his successor Basil I in 867, with some sources stating Basil was Thekla's lover.

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