EU4 Byzantium Guide: Five Ways to Outlive the Ottomans

Byzantium in EU4 opens with the same premise our EU5 Byzantium guide covers a century earlier — a once-great empire reduced to a handful of provinces, penned in by more powerful neighbors — but the 1444 position is starker still: Constantinople, three provinces in southern Greece, and Athens as a vassal, with the Ottomans already the dominant regional power. The wiki labels this page a compilation of strategies rather than settled doctrine, and with five genuinely distinct approaches documented, that framing is accurate — this page presents the standard path in full and the alternatives in outline.

The standard opening: reclaim, ally, survive

Reclaim Epirus first. This two-province Crusader state to your north holds your core Arta, and the wiki flags a real timing quirk: Epirus is usually unavailable as a rival in November 1444 but opens up after the December tick — set only two rivals in November, add Epirus in December, then declare, and you can push past 50 Power Projection by humiliating them in the peace on top of retaking Arta. Vassalizing instead is a legitimate alternative if their fleet matters more to your plans than the humiliation bonus.

Build a ring of small allies before the Ottomans attack. The goal isn’t finding one powerful protector — it’s assembling enough small powers on both sides of the Ottomans that they’re forced to fight a two-front problem. To the west: Serbia (often friendly by default), Albania (worth prioritizing for their 3-star general, though they tend to rival Serbia), then Wallachia, Herzegovina, Bosnia — essentially anyone willing. To the east: Trebizond (their level-3 fort is genuinely time-consuming for the Ottomans to crack) or Circassia/Imereti to divert Ottoman attention into Anatolia. Going well over your diplomatic relation limit here is explicitly the correct play — strong powers won’t ally a weak, differently-faithed Byzantium anyway, so the strategy is quantity from minor powers rather than quality from major ones.

Fight the war defensively. When the Ottomans declare, pull allied forces together rather than fighting alone — the Ottomans’ morale and discipline will stack-wipe isolated armies. Hold Constantinople’s fort (it should survive a long siege) while picking off their secondary army where possible. The real prize isn’t the Ottoman capital — capturing Gallipoli, which controls the strait crossing, is what actually matters, since it lets you blockade the Ottomans out of Europe for the rest of the war and beyond. Bargain for peace around 20-40% warscore rather than dragging the war out; Ottoman rebellions are hard to provoke, and a drawn-out war risks your allies accepting a separate white peace without you.

Consolidate between wars. After the first Ottoman war, use your regained claim on Epirus to work the diplomatic web: vassalize Serbia once their (likely) war with Venice ends, pick up Moldavian provinces via Wallachia if the opportunity arises, and work toward vassalizing Wallachia itself when they eventually break their alliance with you. By the time you’re facing a second Ottoman war, Hungary should be available as a stronger ally, and Georgia can replace Karaman in the east once the latter is gone.

Five documented alternatives

Albania calls for aid — requires some luck: if the Ottomans declare on Venice-guaranteed Albania before attacking you, improve relations (but don’t ally yet, or it may deter the Ottoman declaration), then ally once war starts. A combined Venetian-Naxiote-Albanian-Athenian-Byzantine fleet can achieve naval supremacy over the Ottoman navy, letting you control the Hellespont and Bosporus while building toward a Balkan claim war later — critically, avoiding direct battle with the massive, Janissary-strong Ottoman army throughout.

Abusing the straits — the cleverest documented approach: wait for the Ottomans to march both starting armies into Anatolia (preparing for a beylik war), and if they mothball the Gallipoli fort in the process, land 6,000+ troops backed by a 200+ gun fleet to seize it nearly undefended. With Gallipoli and naval supremacy secured, occupy the rest of the Ottoman Balkans essentially unopposed and negotiate from a position worth up to 100% warscore — reclaiming every core in a single war rather than the standard approach’s several.

Quick Reconquest (“BudgetMonk” strategy) — ally Albania and the Knights immediately, set specific estate privileges (Religious State and Monopoly on Wine for Clergy; Right of Counsel for Nobility; Indebted to the Burghers and Monopoly on Glass for Burghers), then declare a Reconquest war on Selanik with mercenary-heavy siege forces and a strait blockade. Runs on roughly one loan per month — expect to sell titles afterward to recover.

Byzantium Orthodox Horde — an unusual structural approach: start as Crimea, conquer the Byzantine cores from the Ottomans, then release Byzantium as your own vassal and switch to playing it. This combines the strong Byzantine mission tree (leading toward Rome) with horde mechanics and razing, and — notably — an Orthodox horde can still form personal unions through Christian royal marriages. Breaking free of Crimea costs 3 stability, though a coalition war (likely, given the aggressive expansion this route generates) often results in Byzantium being released as a peace term instead, sidestepping that cost.

Holy Roman Option — annex Naples the moment it breaks from Aragon (they’ll typically have no allies to defend them), then relocate your capital there. Sharing a sea tile with nearby HRE-member Italian states lets Byzantium join the Empire on good terms with the Emperor, opening access to a much deeper alliance pool — including a real shot at the Burgundian Inheritance — as a foundation for fending off the Ottomans from a position of Western, rather than purely Eastern, strength.

The endgame: restoring Rome, not just Byzantium

Two decisions define the long game. Restore the Byzantine Empire is the modest one: requires Orthodox faith (or a specific Montferrat national-idea path), Byzantine culture group, and ownership of Constantinople plus twelve other named provinces (including Edirne, Epirus, Athens, and several Anatolian holdings) — achievable well before the true endgame. Restore the Roman Empire is the actual project: owning Roma itself and 425 provinces across the historical Roman borders, at which point your primary culture converts entirely to Roman, you gain Empire rank and a fresh set of national ideas, and — the wiki notes pointedly — the AI will never take this decision. It exists purely as a target for a player determined to rebuild Rome province by province.

Common death spirals

Sources checked

This guide is built on a live self-fetch of the EU4 wiki’s Byzantium page — explicitly labeled a “compilation and strategy article” combining transcluded mechanics with multiple player-submitted strategies, all flagged by the wiki as one of many possible approaches rather than settled doctrine. The Restore the Byzantine Empire and Restore the Roman Empire decision requirements are wiki-verified directly from the game’s own decision conditions.