How to Permanently Delete the Safari History on an iPhone
The Apple iPhone shares much in common with a full-sized computer: it has a desktop, a menu system and a Web browser. The Safari browser on the iPhone works in a very similar manner to the browser on a desktop or laptop computer, keeping a record of every site you visit in its history. If you want to free up storage space on your iPhone or you just want to protect your privacy, you can delete the browser history at any time. It's not necessary to connect with iTunes to erase the data.
Turn on your iPhone and slide the "unlock" tab to the right. Press the button below the screen to return to the home screen.
Tap "Safari." Tap the bookmark icon (it looks like an open book) at the bottom of the screen.
Tap the "History" button and then tap "Clear."
Tap the "Clear History" button to confirm the operation.