diff --git a/BFR/MainWindow.xaml b/BFR/MainWindow.xaml
index 01bcc86..6dc8cf3 100644
--- a/BFR/MainWindow.xaml
+++ b/BFR/MainWindow.xaml
@@ -68,8 +68,8 @@
       <!-- Commit and Undo Buttons -->
       <Border Grid.Row="2" Classes="ConnectUp">
         <Grid ColumnDefinitions="*,*">
-          <Button Grid.Column="0" Content="Undo"/>
-          <Button Grid.Column="1" Content="Rename All"/>
+          <Button Grid.Column="0" Content="Undo" Command="{Binding Undo}" IsEnabled="{Binding !!UndoCount}"/>
+          <Button Grid.Column="1" Content="Rename All" Command="{Binding Commit}" IsEnabled="{Binding IsCommitButtonEnabled}"/>
         </Grid>
       </Border>
     </Grid>
diff --git a/BFR/MainWindow.xaml.cs b/BFR/MainWindow.xaml.cs
index 7d9c3c4..89191cf 100644
--- a/BFR/MainWindow.xaml.cs
+++ b/BFR/MainWindow.xaml.cs
@@ -32,7 +32,7 @@ namespace BFR
             // Filter all files in the directory for those satisfying the given filters
             Files.ReplaceAll(AllFiles.Where(x =>
                 (FilterExtension == "" || x.Extension == FilterExtension)
-                && (FilterFullName ? x.FullName : x.Name).RegexContains(FilterRegex ? FilterPattern : Regex.Escape(FilterPattern))));
+                && (FilterFullName ? x.OldFullName : x.OldName).RegexContains(FilterRegex ? FilterPattern : Regex.Escape(FilterPattern))));
 
             Preview();
         }
@@ -51,15 +51,23 @@ namespace BFR
             foreach (var operation in Operations)
                 operation.ApplyTo(Files);
 
+            // Validate that there are any changes, and that the new file names are all unique.
+            IsCommitButtonEnabled = 
+                Files.Any(x => x.Path != x.OldPath)                    // Check for changes
+                && Files.GroupBy(x => x.Path).All(g => g.Count() == 1) // Check for duplicates
+                && !Files.Any(x => x.FullName == "");                  // Check for invalid file names; TODO: Further validation
+
             // Refresh the file list to guarantee that changes are displayed. TODO: Find a better way to do this.
             Files.ReplaceAll(new List<FileModel>(Files));
         }
 
         public void AddOperation()
         {
-            Operations.Insert(
-                SelectedOperation >= 0 ? SelectedOperation + 1 : Operations.Count,
-                OperationTypes[SelectedOperationType].Create());
+            if (Operations.Count >= 1)
+                Operations.Insert(
+                    SelectedOperation >= 0 ? SelectedOperation + 1 : Operations.Count,
+                    OperationTypes[SelectedOperationType].Create());
+            else Operations.Add(OperationTypes[SelectedOperationType].Create());
             Preview();
         }
 
@@ -81,6 +89,27 @@ namespace BFR
             Preview();
         }
 
+        public void Commit()
+        {
+            foreach (var file in Files)
+                if (file.OldPath != file.Path)
+                    File.Move(file.OldPath, file.Path);
+
+            UndoStack.Push(new List<FileModel>(Files));
+            UndoCount = UndoStack.Count;
+
+            OpenDirectory(WorkingDirectory);
+        }
+
+        public void Undo()
+        {
+            foreach (var file in UndoStack.Pop())
+                File.Move(file.Path, file.OldPath);
+
+            UndoCount = UndoStack.Count;
+            OpenDirectory(WorkingDirectory);
+        }
+
         public MainWindow() => InitializeComponent();
         private void InitializeComponent()
         {
diff --git a/BFR/MainWindowUIProperties.cs b/BFR/MainWindowUIProperties.cs
index f381cf5..157b8e8 100644
--- a/BFR/MainWindowUIProperties.cs
+++ b/BFR/MainWindowUIProperties.cs
@@ -4,6 +4,7 @@ using Avalonia.Controls;
 
 using BFR.DataModels;
 using BFR.Operations;
+using System.Collections.Generic;
 
 namespace BFR
 {
@@ -24,6 +25,14 @@ namespace BFR
             OperationType.Make<Overwrite>()
         };
 
+        public readonly AvaloniaProperty<bool> isCommitButtonEnabled =
+            AvaloniaProperty.Register<MainWindow, bool>("IsCommitButtonEnabled", defaultValue: false);
+        public bool IsCommitButtonEnabled { get => GetValue(isCommitButtonEnabled); set => SetValue(isCommitButtonEnabled, value); }
+        public readonly AvaloniaProperty<int> undoCount =
+            AvaloniaProperty.Register<MainWindow, int>("UndoCount", defaultValue: 0);
+        public int UndoCount { get => GetValue(undoCount); set => SetValue(undoCount, value); }
+        private readonly Stack<List<FileModel>> UndoStack = new Stack<List<FileModel>>();
+
         // Filters
         public string FilterExtension { get; set; } = "";
         public string FilterPattern { get; set; } = "";