Appellant entered guilty pleas to charges under two indictments. On one indictment (case no. A90A0993) he pled guilty to robbery, OCGA 16-8-40 (a), and aggravated assault, OCGA 16-5-21 (a) (2), and received the maximum sentence for each offense, two twenty-year sentences, to be served concurrently. On the second indictment (case no. A90A0994) he pled guilty to making terroristic threats, OCGA 16-11-37 (a), and was given a one-year sentence, the minimum penalty for the offense, to run concurrently with the earlier sentence. He contends on appeal that the sentences were so disproportionate in relation to the facts of the cases as to amount to cruel and unusual punishment.