In ASP.Net, during which page lifecycle event does viewstate get loaded?

It's loaded into memory between init and load. See this article for a full break down of the page lifecycle.

I once got into this question too and got my answer from TRULY understanding Viewstate article, which I highly recommend.

After reading it I designed a graphic that helped me to understand better what was happening on between each stage and when and how ViewState was doing its job.

I'd like to share this graphic with other people that (like myself) need to see how stuff work in a more visual way. Hope it helps! :)

Click on the image to view at full width.