It's well established that Apple's iPhone was in the works for a good two years before it became a household name at Macworld 2007, and interestingly enough, the idea to develop a phone in the first place was borne out of Apple's previous work on tablet prototypes in the early 2000s.

Steve Jobs admitted as much to Walt Mossberg and Kara Swisher during an appearance at the 2010 All Things D conference.

I’ll tell you a secret. It began with the tablet. I had this idea about having a glass display, a multitouch display you could type on with your fingers. I asked our people about it. And six months later, they came back with this amazing display. And I gave it to one of our really brilliant UI guys. He got [rubber band] scrolling working and some other things, and I thought, ‘my God, we can build a phone with this!’ So we put the tablet aside, and we went to work on the iPhone.

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The idea to work on a full-fledged smartphone was of course made easier by Jobs' frustration with the Motorola ROKR, a joint venture between Apple and Motorola that aimed to be part iPod and part phone. When Jobs unveiled the ROKR in September 2005, he underwhelmingly called it an "iTunes Phone" and said Apple viewed the device as an "iPod shuffle right on your phone." Not exactly a strong sell.

Needless to say, the ROKR didn't exactly take the tech world by storm. And in what may be construed as a bit of unintended foreshadowing with respect to the ROKR, take a look at this video from Steve Jobs' September 2005 ROKR introduction where an on-stage demo meant to show how the device automatically resumes music playback once a call ends doesn't quite go as planned. Fast forward to about 3:09 into the video.

Putting those two factors together, Apple's iPhone was effectively the result of two factors; The lackluster product that was the ROKR and Apple's previous work on tablet devices.

Now based on previous reports and deposition testimony, we can say with reasonable certainty that iPhone development began in late 2004/early 2005. Indeed, a 2008 Wired article relayed that Apple's first meeting with Cingular (now AT&T) transpired in February of 2005 where Jobs discussed the notion of a "Motorola-free partnership".

And now, thanks to some digging through some Apple/Samsung court filings, we also have a better grasp as to when Apple's work on tablet prototypes began. What's more, I was able to dig up some photos of one of Apple's early tablet mockups from the early 2000s.

In December 2011, Samsung deposed Apple Senior VP of Industrial Design Jonathan Ive. While the full transcript of that deposition was filed under seal, a portion of it was recently released as part of a declaration from Apple's counsel regarding a Samsung motion seeking to file certain documents of the case under seal.

During the course of the deposition, Ive at one point is shown photos of a three-dimensional mockup of a tablet that Apple produced as part of the discovery process. It's referred to as the 035 mockup or prototype.

Ive is then asked if he'd seen the mockup before, and if so, when.

He responds that he has seen the 035 mockup before and adds:

My recollection of first seeing it is very hazy, but it was, I'm guessing, sometime between 2002 and 2004, some but it was I remember seeing this and perhaps models similar to this when we were first exploring tablet designs that ultimately became the iPad.

So the takeaway is that Apple was tinkering with tablet prototypes as early as 2002.

Next, Ive is asked, "Do you recognize the 035 mockup as a mockup that the Apple model shop produced?"

Ive responds,

I actually don't know which model shop made this, but I recognize this as a model that was produced during our exploration.

Next, Ive is questioned further about the development of the 035 tablet mockup.

Next, Ive is asked if he's aware of any other tablet mockup created prior to March 2004 that is closer to the '889 patent than the 035 mockup. The '889 patent of course is the patent that embodies Apple's iPad and the one Apple is asserting against Samsung.

Ive responds:

I'm not aware of any that are closer or less close. I recall this model; I, of course, recall this patent, and I can see many similarities.

So what did this mysterious 035 mockup actually look like? Well, I looked back at some older filings in the Samsung/Apple case and stumbled across the 035 mockup in question. And now with the added context from Ive's deposition, these photos may be the earliest iPad mockups you'll ever see. And keep in mind that this was a tablet mockup Apple had in the works for years before they introduced the iPad.

Below, you'll note that the mockup is significantly thicker than what Apple eventually ended up shipping in 2010. Also note that there doesn't appear to be a home button on the device.

And just because it's a mockup doesn't mean it doesn't deserve the Apple logo.

And here's where the thickness really shows. It almost looks like an oversized version of an old school iPod.

And now some side angles.

A more head-on view.

I'm not sure why Apple included this photo in the bunch, but it's random enough to warrant inclusion.

Behold! An unidentified man "using" the 035 tablet mockup. He looks confused. Perhaps someone should tell him the device isn't turned on.

And here, a closeup of the mockup's rounded corner.

And so there you have it, what may very well be the oldest known photos of early iPad prototypes from the early 2000s.

Update: New color photos of the 035 mockup have become available