Final answer:
Empress Irene employed diplomacy, fortifications, and naval defense to prevent Abbasid armies from capturing Constantinople.
Step-by-step explanation:
Empress Irene used several strategies to keep Abbasid armies from taking Constantinople. One of the key tactics was her diplomatic skill in negotiating peace treaties and alliances with neighboring kingdoms and empires. She also invested heavily in fortifications and military defenses, including the construction of walls and towers, to strengthen the city's defenses. Lastly, Irene effectively utilized her naval fleet to defend Constantinople from any sea-based attacks.
Learn more about Empress Irene's strategies to protect Constantinople from Abbasid armies