The Third Coalition itself came to Motion full fruition in 1804–05 as Napoleon 's actions in Italy ( crowning Change_of_leadership himself with the Iron Crown of Lombardy ) and Germany ( notably the arrest Arrest and execution of the Duc d'Enghien ) spurred Austria and Russia into joining Becoming_a_member Britain against France .

The Battle Hostile_encounter of Legnano was fought Hostile_encounter between the imperial army of Frederick Barbarossa and the troops of the Lombard League on May 29 , 1176 near the town of Legnano , in present-day Lombardy , in Italy .

In the institutional sphere , the date of May 29 was chosen Choosing as the regional holiday of Lombardy .