This expository paper gives a few historical remarks on the concept of Riordan array and that of Riordan matrix group,which were introduced and expounded in an important paper by Shapiro-Getu-Woan-Woodson in 1991.Also mentioned is the fact that the generalized Stirling number pair and the related pair of reciprocal matrices given in an earlier paper by Hsu in 1989 have actually implied the concepts for Riordan array and Riordan inverse pair of matrices.The major part of this paper presents a brief survey of...