Vertical TextBlock filling verical space

Question

I want to create a TextBlock (or some other element with text in it for display only) that is vertical (-90 transform angle), but I want that element to fill up the vertical space it is contained in, but have a defined horizontal amount (I'm using vertical and horizontal terms instead of height and width since it's swapped when I have the TextBlock go vertical) And have it aligned to the left side of the container.

I believe I understand how to make a TextBlock go vertical using RenderTransform or LayoutTransform. However, I cannot seem to get the 'docking' to work properly, whenever I change the vertical aspect of the container the TextBlock increases in horizontal aspect instead of vertical.

Here is what I have:

<UserControl
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
x:Class="AttendanceTracker.StudentView"
x:Name="UserControl" Height="172.666" Width="417.333">

<StackPanel x:Name="LayoutRoot" Orientation="Horizontal">
 <Border BorderBrush="Black" BorderThickness="1" RenderTransformOrigin="0.5,0.5" Background="#52FFFFFF" Width="139.667">
  <TextBlock Text="My Title" TextWrapping="Wrap" FontSize="18.667" TextAlignment="Center" Foreground="White" Margin="-58.509,68.068,49.158,70.734" Background="Black" RenderTransformOrigin="0.5,0.5" Width="147.017" d:LayoutOverrides="Height">
   <TextBlock.RenderTransform>
    <TransformGroup>
     <ScaleTransform/>
     <SkewTransform/>
     <RotateTransform Angle="-90"/>
     <TranslateTransform/>
    </TransformGroup>
   </TextBlock.RenderTransform>
  </TextBlock>
 </Border>
</StackPanel>

Change the height of the UserControl and you will notice that the TextBlock increases in horizontal aspect instead of the desired vertical aspect.