Amillennialism is the historic Church position. They condemned premillennialism as heresy in 431 at Ephesus.
The earliest position of the early church that we have record of was that there would be a kingdom set up in Jerusalem on the earth-- Papias, Justin, and Ireneaus for example held to a more literal interpretation. Justin said his view was held by all right-minded Christians, but he does not say if amil was one of the positions held by the Christians he did not consider to be right-minded on the issue.
Augustine held to amil, and the view was very popular after him. There was a push toward more allegorical interpretations. Origin used allegorical interpretation. He must have regretted being castrated from too literal an interpretation. But he also held to the idea that literal interpretations were true, too. Augustine, probably learning from Ambrose, held to a bizzare interpretation of II Corinthians 3 that does not fit the text that 'of the Spirit' meant, or was associated, with allegorical interpretation. Augustine was a big proponent of amillennialism and probably one of the reasons it was so popular for a long time afterward.
The apostles also believed that Jesus would restore the kingdom to Israel. They did not say 'kingdom of God' in that question in Acts 1, but something more specific. They asked if, at that time, the Lord would restore the kingdom to Israel. Jesus told them it was not for them to know the times set by His Father, encouraging them in their belief about the restoration of the kingdom to Israel.
So the view is very ancient.