Hi I have a mainView window which has its dataContext set to it's own viewModel. On that viewModel is a DateTime property which in turn is bound to a datepicker on my main view using 2 way binding. <toolkit:DatePicker DateSelected="{Binding mainDateTimeProperty, Mode=TwoWay}" /> This is all fine so far. On the change of my datetime property I create a list which is then bound to a datagrid elsewhere on the mainview. This all works fine. My question is to do with a usercontrol I want to add to the main view. I want this usercontrol to be self contained so have created it with it's own viewmodel but it does also need access to mainDateTimeProperty I thought that best way to go would be to create a dependencyProperty on the usercontrol and when I create my control in the main view I bind the dp to the datetime as follows. <uc:MyNewUserControl DateProperty="{Binding mainDateTimeProperty}" /> Trouble is how do I have the usercontrol maintain datacontext with it's viewmodel and yet still have the dependency property bound to a property on the main view model? Hope this is clear. Can post some more code if necessary. Looking for a best practice approach if possible. Thanks very much for any advice.