Kneading causing gluten
Yes, kneading develops gluten. Specifically, the gliadin and glutenin proteins in flour form gluten when mixed together with water. It's common, but inaccurate (and confusing I think) to refer to gliadin and glutenin as gluten.

For more about the chemistry of how gluten develops see the paragraph on 'bread products' in https://en.wikipedia.org/wiki/Gluten.