PageFlood +

Make sure to allow popups!

Step 1: Drag this tab into a new window.

Step 2: Type in the URL you want to flood your history with.

Step 3: Type how many times you want it to appear in your history. (preferably >100)

Step 4: Press the "Flood" button and unleash the tsunami.

Step 5: Close this window after all the pages load.

Step 5: Congratulations! Your history is now flooded with the URL of choice.