[DPMD]

Maybe now, democrats in the US will be willing to overlook his conduct they earlier described as human rights violations and welcome him into their fold.

[Jack Black]

The earliest known depiction of the Trinity, Dogmatic Sarcophagus, AD 350. Vatican Museums.

The belief in the trinity itself goes back to at least 100 AD, so it's certainly a part of Christian theology from the start, although it's always had opponents.

Wikipedia article: Trinity