WPF Data Binding Errors Getting a System.Windows.Data Error: 40

Question

I keep getting this Error: System.Windows.Data Error: 40 : BindingExpression path error:

System.Windows.Data Error: 40 : BindingExpression path error:

• 'ViewModels' property not found on 'object' ''MainWindow' (Name='')'.

• BindingExpression:Path=ViewModels.EventViewModel.EventName;

• DataItem='MainWindow' (Name='');

• target element is 'ComboBox' (Name='EventNameComboBox');

• target property is 'SelectedItem' (type 'Object')

MainWindow.XAML

    <ComboBox Name="EventNameComboBox"
              DisplayMemberPath="EventName"
              HorizontalContentAlignment="Center"
              ItemsSource="{Binding Path=EventViewModels}"
              materialDesign:HintAssist.Hint="Select an Event"
              SelectionChanged="EventNameComboBox_SelectionChanged"
              Width="400">
        <ComboBox.SelectedItem>
            <Binding Path="ViewModels.EventViewModel.EventName" UpdateSourceTrigger="PropertyChanged">
                <Binding.ValidationRules>
                    <validationRules:EventNameValidationRule ValidatesOnTargetUpdated="True"/>
                </Binding.ValidationRules>
            </Binding>
        </ComboBox.SelectedItem>
        <ComboBox.ItemsPanel>
         <ItemsPanelTemplate>
             <VirtualizingStackPanel/>
         </ItemsPanelTemplate>
        </ComboBox.ItemsPanel>
    </ComboBox>

EventNameValidationRule.cs

public class EventNameValidationRule : ValidationRule
{
    public override ValidationResult Validate(object value, CultureInfo cultureInfo)
    {
        string eventName = value == null ? "" : value.ToString();

        return string.IsNullOrEmpty(eventName)
            ? new ValidationResult(false, "Please select a Event")
            : ValidationResult.ValidResult;
    }
}

Finally,

EventViewModel.cs

public class EventViewModel : INotifyPropertyChanged
{
    private int _eventId;
    private string _eventName;


    public int EventId
    {
        get { return _eventId; }
        set
        {
            _eventId = value;
            OnPropertyChanged("EventId");
        }

    }

    public string EventName
    {
        get { return _eventName; }
        set
        {
            _eventName = value;
            OnPropertyChanged("EventName");
        }
    }


    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

I'm not sure what is going on.

UPDATE

MainWindow.xaml.cs

private List<EventViewModel> _eventViewModels;

public List<EventViewModel> EventViewModels
{
    get { return _eventViewModels; }
    set { _eventViewModels = value; OnPropertyChanged("EventViewModels"); }
}

public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
    PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}


public MainWindow()
{
    InitializeComponent();

    EventViewModels = new List<EventViewModel>();
    int year = 2008;
    for (int i = 1; i <= 10; i++)
    {
        EventViewModel viewModel = new EventViewModel();
        viewModel.EventId = i;
        viewModel.EventName = $"{year} Test Event";

        ++year;

        EventViewModels.Add(viewModel);
    }

    DataContext = this;
}