Original: Siena 's republic , struggling internally between nobles and the popular party , usually worked in political opposition to its great rival , Florence , and was in the 13th century predominantly Ghibelline in opposition to Florence 's Guelph position ( this conflict formed the backdrop for some of Dante 's Commedia ) .
Simplified: Siena 's republic , struggling internally between nobles and the popular party , usually worked in political opposition to its great rival , Florence .