Yes there is an event LoadComplete()
protected void Page_LoadComplete(object sender, EventArgs e)
This event is for tasks that require that all other controls on the page be loaded.
Suppose I have to show messages on page and then I have to redirect to some other page.
I Have a small example; I have a page which connect me to some more URL’s but to some reasons I have shift that page to another location.
Now I have to show message on page
“this page has shifted to another location. This page will automatically redirect to another page”
So, this can be done only after page load so, this is the best event to place that code