While no proposed date for the composition of Acts is universally accepted, the most common scholarly position is to date Luke–Acts to 80-90 CE on the grounds that he used Mark as a source. He looked back on the destruction of Jerusalem, and does not show any awareness of the letters of Paul, that began circulating late in the first century. The earliest possible date for the composition of Acts is set by the events with which it ends, Paul’s imprisonment in Rome around 63 CE, but such an early dating is a minority position. The last possible date would be set by its first definite citation by another author, but there is no unanimity on this. Some scholars find echoes of Acts in I Clement from 95 CE, the letter of Clement of Rome who died in 99 CE, while others see no indisputable citation until the middle of the 2nd century.