The area of Sondrio was populated 
							in ancient times by the
							
							Ligures and, from the 5th century BC, by the
							
							Celts. Formerly an
							
							Ancient Roman military camp, today's Sondrio was 
							founded by the
							
							Lombards: in their language Sundrium 
							meant "Exclusive property", referring to the status 
							of free men (arimanni) 
							of the holders of the city and the surrounding land.
							After the fall of the
							
							Lombard Kingdom in Italy, Sondrio became part of 
							the
							
							Holy Roman Empire. The Capitanei of Vizzola, who 
							controlled much of the Valtellina, had it in 1040 
							from the emperor
							
							Henry II. From 1310 to 1335 the city was 
							involved in the war between the
							
							Guelph and Ghibelline factions of the nearby
							
							Como, and its war against
							
							Milan. After having resisted several attacks by 
							the Comaschi, in 1335 Sondrio and Valtellina became 
							part of the
							
							Visconti Milanese dominions.
							From the second half of the 
							16th Century to the 18th Century, Sondrio was 
							governed by the Tre Leghe Grigie ("Three Grey 
							Leagues") of the
							
							Grisons, as the capital city of
							
							Valtellina. After the
							
							Reformation, Sondrio was the centre of heavy 
							struggles between the Catholic Valtellinesi and the 
							Protestant Grisons. In 1620 the citizens, led by
							
							Giacomo Robustelli, killed 180 Protestants and 
							declared the independence of the Valtellina.
							After the
							
							Napoleonic parenthesis, in which it was annexed 
							to the
							
							Cisalpine Republic, Sondrio fought gallantly 
							with the Austrian
							
							Kingdom of Lombardy-Venetia for its 
							independence.