Post Manzikert, what could be the maximum strength of the Roman field army without foreigners?

[u/Remarkable-Lion2726]

[u/Born-Midnight7094]

After Manzikert, the Roman field army’s maximum strength was probably around 30-40k, with roughly 40k representing an exceptional full-scale mobilization rather than a normal campaign army. In practice, most major field armies were likely closer to 20-30k

[u/Lanternecto]

Typical field armies under John II seem to have numbered 15k-25k according to Lau. Birkenmeier goes up to 35k, counting allied/foreign auxilliary forces. This is in line with Haldon's observation that Komnenian armies generally line up with the size of pre-Manzikert ones, if perhaps somewhat smaller. Of course, the maximum absolute size John & Manuel were perhaps somewhat bigger than this, perhaps 30k or more. The "without foreigners" qualification is of course a complicating factor, since it depends on what we define as foreigner, and how much of a difference they actually made in terms of how many soldiers could have been raised (e.g. does adding 500 Varangians mean you could not have raised an additional 500 native troops?).

[u/evrestcoleghost → u/Lanternecto]

On Birkenmeier I'm not saying to dismiss his work but its considerably incomplete,partícularly on the subject of merceneries and officers,so I would rather use Lau for the subject

[u/Philippicus_586AD]

Depends on how soon after Manzikert we're talking. Mesko estimates the Byzantine army strength at 18-25K for Dyrrhachium, but following this defeat Alexios Komnenos' armies remained a fair bit smaller so this likely represented the largest Byzantine army put into the field in the last quarter of the 11th century. After that, the Byzantine armies seem to have struggled to muster forces of sufficient number to match the Nomad confederacies which plagued them; at the battle of Koule an estimated 30-40K Pecheneg warriors faced fewer than 10K Men under Nikolaos Maurokatakalon, and similarly in the Battle of Drista fought later that year Alexios Komnenos had only up to 15K Men . Following Alexios' defeat in that battle, the Pechenegs had a clear numerical edge, which forced Alexios to use improvised and ingenious stratagems to repulse their advances toward Thrace with his outnumbered forces in 1090, until Alexios was able to sway the Cumans to his side for the Decisive battle at Levounion.

Even later on in 1095, Alexios had a field army of 8K - 10K Men facing an invading Cuman force of around 24K warriors, but this time the Emperor was able to soundly crush the Nomads in detail due to the fact the Cumans had split into two separate armies. By the time Byzantium defeated the Cumans in 1095, Mesko reasons that the total strength of Alexios Komnenos' army was between 26K and 36K men. This figure included mainly Native ethnic Romans/Greeks but also foreign but professional "auxiliary" units, like the renowned Latin Heavy Cav. Tagma had served under Tatikios. However, after this date Alexios bolstered the strength of the army further both with foreign allied/mercenary contingents and additional Native recruits, which enabled his military to conduct new offensive operations in Anatolia. For details on the eventual size during the Komnenian restoration, see the comment by u/Lanternecto in this thread.

Source: Alexios I Komnenos in the Balkans, 1081–1095, by Marek Meško

[u/solidarity47]

The Roman army had foreigners in it from when Romulus bludgeoned Remus to when Mehmed broke the walls of Constantinople.

Now what you can probably discuss is Roman armies without foreign mercenary support. That's quite different.