Byzantines/Tree

The Byzantines have access to the following buildings, units and technologies:

Archery Range
Units Technologies
 * Archer -> Crossbowman -> Arbalest
 * Skirmisher -> Elite Skirmisher
 * Hand Cannoneer
 * Cavalry Archer -> Heavy Cavalry Archer
 * Thumb Ring

Barracks
Units Technologies
 * Militia -> Man-at-Arms -> Long Swordsman -> Two-Handed Swordsman -> Champion
 * Spearman -> Pikeman -> Halberdier
 * Tracking
 * Squires
 * Arson

Stable
Units Technologies
 * Camel -> Heavy Camel
 * Knight -> Cavalier -> Paladin
 * Scout Cavalry -> Light Cavalry -> Hussar
 * Husbandry

Dock
Units Technologies
 * Fishing Ship
 * Trade Cog
 * Fire Ship -> Fast Fire Ship
 * Transport Ship
 * Demolition Ship -> Heavy Demolition Ship
 * Galley -> War Galley -> Galleon
 * Cannon Galleon -> Elite Cannon Galleon
 * Gillnets
 * Careening -> Dry Dock
 * Shipwright

Watch Tower
Can be upgraded to:
 * Guard Tower -> Keep

Stone Wall
Can be upgraded to:
 * Fortified Wall

Monastery
Units Technologies
 * Monk
 * Redemption
 * Fervor
 * Sanctity
 * Atonement
 * Heresy
 * Block Printing
 * Illumination
 * Faith
 * Theocracy

Castle
Units Technologies
 * Cataphract -> Elite Cataphract
 * Petard
 * Trebuchet
 * Greek Fire
 * Logistica
 * Hoardings
 * Conscription
 * Spies/Treason

Town Center
Units Technologies
 * Villager
 * Town Watch -> Town Patrol
 * Feudal Age -> Castle Age -> Imperial Age
 * Loom
 * Wheelbarrow
 * Hand Cart

Siege Workshop
Units
 * Mangonel -> Onager
 * Battering Ram -> Capped Ram -> Siege Ram
 * Scorpion
 * Bombard Cannon

Blacksmith
Technologies
 * Padded Archer Armor -> Leather Archer Armor -> Ring Archer Armor
 * Fletching -> Bodkin Arrow -> Bracer
 * Forging -> Iron Casting
 * Scale Barding Armor -> Chain Barding Armor -> Plate Barding Armor
 * Scale Mail Armor -> Chain Mail Armor -> Plate Mail Armor

University
Technologies The Byzantines do not have Masonry or Architecture, but they get better bonuses for building HP. Masonry gives +10%, and Architecture gives a total of +21%. However, in the Castle Age, the Byzantines get +30% HP (more than Architecture), and in the Imperial Age, they get +40% (almost double Architecture). The only loss is that the technologies grant additional building armor, whereas the civilization bonus does not.
 * Fortified Wall
 * Chemistry -> Bombard Tower
 * Ballistics
 * Guard Tower -> Keep
 * Murder Holes

Mining Camp
Technologies
 * Stone Mining -> Stone Shaft Mining
 * Gold Mining -> Gold Shaft Mining

Lumber Camp
Technologies
 * Double-Bit Axe -> Bow Saw -> Two-Man Saw

Market
Units Technologies
 * Trade Cart
 * Cartography -> Caravan
 * Guilds
 * Coinage -> Banking

Mill
Technologies
 * Horse Collar -> Heavy Plow -> Crop Rotation