<Canvas x:Name="root" 
  Loaded="OnLoaded" 
  xmlns="http://schemas.microsoft.com/client/2007"  
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Width="400" Height="400">

  <Rectangle x:Name="rect1" Canvas.Top="10" Canvas.Left="10" Width="30" Height="30" Fill="red"/>
  <Rectangle x:Name="rect2" Canvas.Top="50" Canvas.Left="10" Width="30" Height="30" Fill="black" />

    <Canvas.Triggers>
      <EventTrigger RoutedEvent="Canvas.Loaded">
        <EventTrigger.Actions>
          <BeginStoryboard>                                                                                                                                               
            <Storyboard  
                  Storyboard.TargetName="rect1"
                  Storyboard.TargetProperty="(Canvas.Left)"
                  BeginTime="0:0:1"
            >
              <Storyboard
                  Storyboard.TargetName="rect2">
               
		<DoubleAnimation 
                  BeginTime="0:0:1"
                  Storyboard.TargetProperty="(Canvas.Left)"
                  Duration="0:0:3"
                  To="200" 
                />
	</Storyboard>
		<DoubleAnimation 
                  BeginTime="0:0:1"
                  Storyboard.TargetProperty="(Canvas.Left)"
                  Duration="0:0:3"
                  To="150" 
                />
	</Storyboard>
	</BeginStoryboard>
	</EventTrigger.Actions>
	</EventTrigger>
	</Canvas.Triggers>

</Canvas>
