First of all I’d like to express my thanks to Professor Nicola Bergamo for helping me regarding the resignation of patriarch Germanus I of Constantinople (r. 715-730).
Old wisdom claims Iconoclasm (actually it should be called iconomachy; this will be treated in a future post) was started being promoted by the Roman Emperor Leo III (r. 717-741) as an answer to Islam and the huge disasters of the 7th century, after the eruption of Thera in 726, in a series of edicts until 729. It is also claimed he faced revolts from the iconophile provinces and entered a dispute with the Pope over these matters, which made him take away the bishoprics of southern Italy and Illyricum as well as church incomes from papal lands in Sicily. 
This might all seem very impressive, but this theory has several problems, as Leslie Brubaker and John Haldon outlined.  First of all the narrative sources available for Leo’s reign, most are from the 9th or 10th centuries and have axes to grind against the Isaurians for their promotion of Iconoclasm.  This means Theophanes’ Chronographia, for instance, is far from neutral and reliable on this period, as several other instances of the Isaurians’ reign, where contradicting evidence exists, prove.  The only 8th century reference to his iconoclasm is allegedly in the Liber Pontificalis, which records Papal conflict with Leo, however the passages referring the emperor’s religious belief suffered from later interpolations, making the text as reliable as our chronistic Roman sources.
To add to this scenario, we have the letters of patriarch Germanos (r. 715-730), that, despite the problems of such epistolary kind of evidence , are especially important for the case given his contemporaneity and his political role, especially if we have into account the story he was deposed for resisting iconoclasm. In one letter written in the 730’s to Thomas of Klaudiopolis (a real Iconoclast), he wrote Leo III and his son Constantine V had ordered an icon of the apostles, prophets and the cross to be made in front of the imperial palace.  Since the Isaurians weren’t exactly popular after the end of the second controversy around iconomachy, the likelihood of this text being an invention is extremely low. As such, it introduces quite a different and startling conclusion: the founder of the Isaurian dynasty was an iconodule who suffered from character murder! 
Someone might object Germanos was deposed due to the iconoclasm of the Emperor, but this story was the result of later constructions with either defaming or moralistic ends, just like many others, including the story of the women on the Chalke Gate killed by the imperial guards and the reasons for the revolts during his reign as well as his disputes with the Pope. Regarding the patriarch of Constantinople, he was forced to resign not because he opposed to iconoclasm, but instead because he sought a hard line against bishops such as Thomas, while Leo wanted an ecumenical council to solve the issue and avoid aggravating the controversy as it was in the late 720’s. This made the emperor issuing a law forcing both sides to commit themselves to a Council and respect its outcome. It was Germanos’ opposition to it that provoked his resignation as Patriarch and exile. Later his story would be used and rewritten by the iconodules to serve as a model case of opposition to imperial heresy.
The rebellion of the Karabisianoi and the theme of Hellas in 727, like any rebellion at the time, should also be seen not as a riot of iconodule vs. iconoclast conflict (in my view pure imagination by modern historians), but instead as another riot for political and economic power (characteristic of the Roman Empire in this age) intended purely to overthrow the Roman Emperor and replace it with a general named Kosmas. Finally, the Popes never entered in conflict with Leo III over religious policy and actually kept a quite polite and friendly policy notwithstanding any divergence with the imperial court. The matters of conflict at hand were just over Papal incomes and grain (confiscated in 732 by an imperial army due to financial reasons as well as religious jurisdiction in southern Italy and Illyricum and that’s visible in the Liber Pontificalis, although it’s possible they might have viewed the conciliatory imperial policy of Leo with concern by 731. 
Concluding, Leo III, as far as we really know, wasn’t iconoclast at all. He was a man of his age who, according to patriarch Germanos, was an iconodule and assisted to the rise of Iconoclasm as a conservative movement designed to counter the innovations around icons (as in a future post we’ll see, icons didn’t have the religious power they had later on in the Christian church up to the late 7th century). Since Constantine V was the emperor who started imperial support of iconoclasm and the Isaurians had a very good military record (which led to the second iconoclast period in the 9th century), the founder of the dynasty was vilified by chroniclers such as Theophanes the Confessor, Patriarch Nikephoros I or Stephen the Deacon. Usually Leo III is remembered for iconoclasm, however I propose something different: let’s remember him as a cunning man who managed to rise to the throne under very hard circumstances, defend Constantinople during the siege of 717-718 (stopping therefore Umayyad expansion against Rome and preventing any possible annexation by the Muslim Caliphate), start the process of stabilization of the Roman borders seen in the 8th and early 9th centuries, make administrative reforms and issue a new law code that simplified and actualized Justinian’s Corpus Iuris Civilis, called the Ekloge. In sum, a great emperor who made the Isaurian Renaissance possible.
 A good example of the way how Leo III is traditionally depicted is in Treadgold’s A History of the Byzantine State and Society, pp. 346-356.
 Brubaker and Haldon 2011, pp. 69-155.
 Brubaker 2012, p. 28-30; Whittow 1997, p. 143.
 A nice example of this is the supposed anti-monasticism of Constantine V. Actually we know he was a patron of several monastic communities and the monks he persecuted were actually political enemies probably involved in the coup against him in 765/6. See for further informations Whittow 1996, pp. 147-148 and Brubaker 2012, pp. 47-49.
 Whittow 1996, pp. 4-7.
 Brubaker 2012, p. 24.
 Regarding the damnatio memoriae inflicted on the Isaurians, check Bergamo, La Familia Dannata: Leone III e Costantino V, Vita di Due Empi Tiranni, Imperatori di Bizancio, in Porphyra no. 15, fascicle no. 2.
 Brubaker and Haldon 2011, pp. 85-86.
Brubaker, Leslie; Haldon, John. Byzantium in the Iconoclast Era, c. 680-850: A History. Cambridge University Press, 2011.
Brubaker, Leslie. Inventing Byzantine Iconoclasm. Bristol Classical Press, London, 2012.
Bergamo, Nicola, La Familia Dannata: Leone III e Costantino V, Vita di Due Empi Tiranni, Imperatori di Bizancio, in Porphyra no. 15, fascicle no. 2.
Whittow, Mark, The Making of Orthodox Byzantium, 600-1025. California University Press, Los Angeles, 1996.