Latin League invasion of Balkan (Premysloides Dynasty)

Background
Latin League was movement formed as reaction against Most Serene Republic of Marmaria. Dissatisfied Latin, Catholic and Frankish lords revolted against republican government and successfully unified their forces in movement called "Latin League", inspired by north Italian Lombard League. Most of Latin League members were crusaders, landlords, latin aristocracy and allies of Venetia. Venetia later joined Latin League and became hegemon of League.

Latin League invasion of Balkan had two main goals: Elimination of competing Republic and possible rising new power of Xanthi Kingdom and prepare joint war with Latin Empire against Nicean Empire.

War
Two main elements of anti-Latin forces were Republic of Marmaria and Kingdom of Xanthi. Both of them had neutral relations with Nicean Empire and Emperor Romanos, both of them had various forces and strenghts, or weakness.

Republic of Marmaria was weakest participant of war. Democratic and very complicated system of power within Republic of Marmaria, with many tactical military mistakes, poor leadership and inefficient administration led to swift decline and collapse of Marmaria Republic with minimal casualties for Latin League, except Bulgarian cities of Marmaria Republic, which were able to held some struggle and few weeks even repeled some of Latin attacks.

Main resistance on Balkan was formed around ambitious Kingdom of Xanthi, which had numerous military and economical resources and competent rulership. On other hand, Xanthi very underestimated Latin League forces and decided to besiege and invade Constantinople. Xanthi army was crushed when Latin League army attacked siege camps in rear and massacred most of Xanthi army.

For Venetia, this war was crucial also in other meaning. Venice was great naval superpower, but never achieved land supremacy and victories. Balkan invasion was political move as Venice wanted to persuade whole world about their military capabilities not just on sea, but also on land. Latin League invasion on Balkan ended with decisive victories and only very small casualties for invaders.

Aftermath
Defeat of Xanthi and Marmaria, plundering and razing, led to declaring martial law in Nicean Empire and transfer of imperial army to Thessaloniky, largest and most prosperous Nicean city in Greece. At Thessaloniky, War for Imperial Restoration was decided.