Women and eunuchs
The existence of what has been called the "third sex" in Byzantium, the eunuchs, could be useful for women in giving them an alternative cross-dressing option.
I've commented elsewhere on how eras of gender-distinctive clothing could help women disguise themselves, but passing as a eunuch was even easier - no need to lower your natural voice tone or even pretend to shave. And since eunuchs could become monks, hermits, priests and even in at least two cases patriarchs, there were plenty of career choices available.
So women in Byzantium "pursued their dedication to the spiritual life. In numerous stories written about them, they fled arranged marriages, repented of their previously unchristian lives as prostitutes and sought refuge in monasteries of men, where their angry relatives were least likely to come looking for them." (p. 109)
Among them were St Eugenia, who in a typical twist in the tale was accused of adultery as a man, and St Euphrosyne, who offers spiritual counsel to her own father without being recognised.
Characteristic of the "reformed" group is St Pelagia of Antioch, said to have died 481 who after a successful career as a prostitute. She "gave away to the poor the enormous wealth she had amassed by her immorality and went secretly to Jerusalem, where, under a man's name as the monk Pelagius, she shut herself in a cell on the Mount of Olives and there began a strict ascesis of fasting, prayer and vigils."
It is interesting that such gender-bending behaviour was treated approvingly by the church - these stories would have been read out on the saints' holy days. But of course it couldn't last ...
"By the eighth century, the pattern of creating female Byzantine saints had changed radically and early Christian opportunities for travel, pilgrimage or pursuing a solitary or communal life disguised as a eunuch had been gradually removed. Women could still be sanctified by martyrdom, by demonstrations of excessive piety and good works, especially if miracles occurred at their tombs, but it was no longer considered suitable for them to adopt the disguise of the eunuch." (p. 110)
Which doesn't mean of course that they didn't do it.
From Judith Herrin, Women in the Purple, Rulers of Medieval Byzantium, Wiedenfeld & Nicolson, London, 2001.