Solidus, Christ, Justinian II, 'Abd al-Malik, Image
It is argued that the reason why Justinian II began striking solidi depicting the bust of Christ on the obverse with a legend identifying him as the rex regnantium ‘King of Those that Rule’ is that he thought that the Second Coming of Christ and Last Judgement were at hand following the beginning of the construction of the Dome of the Rock on the Temple Mount in Jerusalem. It is also argued that the reason why Justinian changed from using one style of bust of Christ to another is that the first bust of Christ seemed too similar to the depiction of the caliph on the so-called Standing Caliph series of coins when that began to be struck.