The rivalry with Montone and the end of rivalry with Oca:
The rivalry between Nicchio and Valdimontone is one of the oldest. Faded over time, it regained its body only in the fifties, with the extinction of the one between Oca and Nicchio, which followed the breaking of the "TONO". The first disagreements between Nicchio and Valdimontone date back to 1700. However, relations between the two Contradas were not always tense: apart from some nineteenth-century clashes, there was a long period of tranquility that lasted until the thirties. Later, although Nicchio absorbed a large part of his energies for the rivalry with Oca, there was no lack of episodes that consolidated the enmity with Montone, which became official in 1952. This situation still creates an anomaly among the niches: while for the older generations the rival remains Oca, the young give weight to the only "official" rivalry with the Montone, which is currently deeply felt.
From: Wikipedia, l'enciclopedia libera.