Volume 1 of Craig Keener’s massive commentary on Acts just arrived at the library. While skimming it, I came across his discussion on tongues. I’ll quote just a bit of it:

Iraenaeus (Her. 5.6.1; Euseb. H.E. 5.7.6) claimed that the gift continued in his day…Tertullian, before he became a Montanist, also argued that tongues continued among the orthodox (Marc. 5.8); Novatian (De Trinitate 2.9) and Ambrose (The Holy Spirit 2.150) spoke of tongues in the present tense, in the very period when John Chrysostom and Augustine thought that the gift had finally died out. (pp. 812-813)

It appears that we have evidence of the continued practice of speaking in tongues from NT times to at least the late fourth century. From a Charismatic-Pentecostal perspective this is very exciting. I am curious when speaking in tongues did die out, if it truly did.