Complex sentence: Pettinaio died on 4 December 1289 at an advanced age and was buried at the Franciscan church in Siena-his grave soon became a pilgrimage site and the scene of miracles.
Split into simpler sentences: Pettinaio died on 4 December 1289 at an advanced age and was buried at the Franciscan church in Siena. His grave soon became a pilgrimage site and the scene of miracles.