Picker ItemsSource not binding

I'm attempting to bind a Picker to an ObservableCollection and nothing displays. I have set up a second property, CategoryCount, to return the count of the collection, which correctly shows 2.

    <StackLayout Spacing="20" Padding="15">
        <Label Text="Category" FontSize="Medium" />
        <Picker ItemsSource="{Binding CategoryList}"  ItemDisplayBinding="{Binding Name}" SelectedItem="{Binding Item.Category}" />
        <Label Text="Category Count"/>
        <Label Text="{Binding CategoryCount}"/>
    </StackLayout>


public class ItemDetailViewModel : BaseViewModel
 {
    public ObservableCollection<Category> CategoryList;
    public string CategoryCount
    {
        get
        {
            return CategoryList.Count.ToString();
        }
    }
    public LedgerEntry Item { get; set; }

    public ItemDetailViewModel(LedgerEntry item)
    {
        Item = item;
        CategoryList = new ObservableCollection<Category>()
        {
            new Category(){Id = 1, Name="test"},
            new Category(){Id = 2, Name = "hallo"}
        };
        OnPropertyChanged("CategoryList");
    }
}


public class Category
  {
     public int Id { get; set; }
     public string Name { get; set; }
  }

I've tried changing it to a List of strings with proper values, and could not get that working either. Any thoughts on why I'm having this issue?