ASP.NET Page Life Cycle, event order, master page, page and control events order

    PAGE: Page.OnPreInit()
        USER CONTROL: UserControl.OnInit()
MASTER PAGE: MasterPage.OnInit()
    PAGE: Page.OnInit()
    PAGE: Page.OnInitComplete()
    PAGE: Page.OnLoad()
MASTER PAGE: MasterPage.OnLoad()
        USER CONTROL: UserControl.OnLoad()
    PAGE: Page.OnLoadComplete()
           Page Event Handlers
    PAGE: Page.OnPreRender()
MASTER PAGE: MasterPage.OnPreRender()
        USER CONTROL: UserControl.OnPreRender()
    PAGE: Page.OnPreRenderComplete()
    PAGE: Page.OnSaveStateComplete()
        USER CONTROL: UserControl.OnUnload()
MASTER PAGE: MasterPage.OnUnload()
     PAGE: Page.OnUnload()

More information here:
ASP.NET Page Life Cycle