According to all four gospels, during the Last Supper, Jesus told Peter he would deny all knowledge of him three times before cock's crow the next morning. Peter, the Bible tells us, retorts that he would never disown Jesus.
After Christ’s arrest, Peter did indeed refuse to acknowledge his leader. It was only after a third protestation that a rooster crowed, and Peter burst into tears as he recalled Christ’s prediction.
St Peter’s repentance led to his becoming the first Pope. His symbol, the cockerel, was later deemed by Pope Gregory I (AD 590-604) to be a suitable Christian emblem, and some churches started to use roosters as ‘weather-cocks’. In the ninth century, Pope Nicholas I (AD 858-867) decreed the badge should be displayed on all churches and many incorporated the design into weather vanes.
The oldest weather-cock is the Gallo di Ramperto, forged between AD 820 and 830. It was displayed on the bell tower of the Church of Saints Faustino and Giovita in Brescia, Italy, until 1891, when it was moved to the town's museum.