0:16:28 > 0:16:32At the end of the 13th century, an English King invaded Wales,
0:16:32 > 0:16:37determined the locals would submit to his divine right to rule.
0:16:37 > 0:16:42On this spiritual shore, Edward I of England hatched a devilish plan
0:16:42 > 0:16:48to enshrine his authority over the Welsh - in stone!
0:16:49 > 0:16:54What a piece of work and truly awe-inspiring.
0:16:54 > 0:16:55It looks terrifying now,
0:16:55 > 0:17:00but can you imagine what it would have looked like 800 years ago?
0:17:02 > 0:17:07I want to bring this building back to its former glory and discover
0:17:07 > 0:17:11what made this one of Britain's most formidable fortresses.
0:17:16 > 0:17:20Although the stone walls are largely intact,
0:17:20 > 0:17:25Harlech Castle has been stripped of its strongest defence -
0:17:25 > 0:17:28the sea.
0:17:28 > 0:17:32Back when it was built, I would have been walking on water,
0:17:32 > 0:17:35not the sand dunes that are here now.
0:17:38 > 0:17:41Rhian Parry knows what's happened to the coast
0:17:41 > 0:17:44since the castle was constructed.
0:17:45 > 0:17:49We do know from this map of 1610 by Speed
0:17:49 > 0:17:52that it was quite a different picture.
0:17:52 > 0:17:54You can see, here's the castle.
0:17:54 > 0:17:57Look, we're presumably somewhere by that mermaid.
0:17:57 > 0:18:00And look at the ships going in and out of the estuary.
0:18:00 > 0:18:04The tradition is, and there's some documentary evidence, of course,
0:18:04 > 0:18:08that there was a port for Harlech at Ynys at Ty Gwyn y Gamlas,
0:18:08 > 0:18:12which literally means the white house of the canal,
0:18:12 > 0:18:15and it's likely that this was all marsh
0:18:15 > 0:18:18and at high tide it was underwater completely.
0:18:18 > 0:18:21- So, Ynys island is... - Yes, is this one here.
0:18:21 > 0:18:25So, if that was an island then, in the medieval period,
0:18:25 > 0:18:27this was all marsh and open water.
0:18:27 > 0:18:29Indeed and there are lots of little islands
0:18:29 > 0:18:31and the place names tell you that they were islands
0:18:31 > 0:18:33and people didn't call them islands for nothing.
0:18:33 > 0:18:39Restoring the sea to lap against the walls of Harlech castle
0:18:39 > 0:18:42is step one of my medieval makeover.
0:18:42 > 0:18:50This is how it looked when Edward I of England built it to conquer the Welsh.
0:18:50 > 0:18:55But the sea was more than a barrier. It was also a gateway.
0:18:55 > 0:18:58Andrew, why have you brought me to this lump of masonry?
0:18:58 > 0:19:02The name is explanatory in itself - this was the water gate,
0:19:02 > 0:19:04and the implication is that the water
0:19:04 > 0:19:06was adjacent to it.
0:19:06 > 0:19:11The sea actually lapped up onto the side of these rocks?
0:19:11 > 0:19:14It did. So you've got to imagine water down here.
0:19:14 > 0:19:17- With jetties and ships and everything? - Certainly a bustling harbour,
0:19:17 > 0:19:20because they had an enormous amount of material to get up.
0:19:20 > 0:19:23All the stone they were bringing in, the iron they were bringing in, food.
0:19:23 > 0:19:27- They were feeding 900 men, at one point.- So how do you get up there?
0:19:27 > 0:19:30There's a path that goes up and I'll show you where that is.
0:19:30 > 0:19:35The site of the castle starts to make sense.
0:19:35 > 0:19:40With water guarding one side and steep slopes on the other,
0:19:40 > 0:19:44there was only one way in - a landward gate
0:19:44 > 0:19:46which was heavily fortified.
0:19:47 > 0:19:49Look at this, those towers!
0:19:49 > 0:19:52There's one, two, three, four towers?
0:19:52 > 0:19:55Yeah. They give an enormous aspect, don't they?
0:19:55 > 0:20:00Any attacker who got this far would have to breach the gatehouse,
0:20:00 > 0:20:04a massive defensive obstacle that dominates the castle.
0:20:04 > 0:20:08You're making a huge statement, that this is the strongest bit.
0:20:08 > 0:20:10Yeah, very definitely.
0:20:10 > 0:20:13And this is sort of the chamber where...
0:20:13 > 0:20:15This is the worrying chamber where you didn't want to be.
0:20:15 > 0:20:18- Two arrow slits. - Two arrow slits either side.
0:20:18 > 0:20:20So, crossbows would have come through there.
0:20:20 > 0:20:22You've got iron gate there, iron gate there...
0:20:22 > 0:20:25- And attack from above as well. - Murder holes.
0:20:25 > 0:20:27- Murder holes pouring down onto you. - Boiling oil...
0:20:27 > 0:20:29Yeah, that sort of thing.
0:20:31 > 0:20:35This concentric design, walls within walls,
0:20:35 > 0:20:38held back the hostile Welsh nearby.
0:20:41 > 0:20:44That's the Snowdonia range of mountains over there, and there's Snowdon.
0:20:44 > 0:20:47And this was of course the Welsh stronghold
0:20:47 > 0:20:49of the Princes of Gwynedd.
0:20:49 > 0:20:54This was the real point that Edward had to get to, the bit he had to crack.
0:20:54 > 0:20:55So what was his big idea?
0:20:55 > 0:20:57He was going to encircle it with castles.
0:20:57 > 0:21:00So Harlech is one, Caernarvon is the other on the north
0:21:00 > 0:21:03and then you've got Conwy, and then slightly later,
0:21:03 > 0:21:05Biwmares was built as well.
0:21:05 > 0:21:09And this really represented, finally, the conquest of the Welsh.
0:21:09 > 0:21:12It did, yes, yes, very definitely.
0:21:13 > 0:21:17It's likely the grey stone walls of Harlech Castle
0:21:17 > 0:21:19looked very different in its heyday.
0:21:19 > 0:21:25Edward had the structure plastered with a white render of lime mortar.
0:21:26 > 0:21:31Wouldn't it be great to lime wash the castle bright white?
0:21:31 > 0:21:34But I guess no-one's actually going to let me do that,
0:21:34 > 0:21:40but I have found a wall just down the road where we can try the stuff out.
0:21:40 > 0:21:44The castle's coating of lime render was probably finished off
0:21:44 > 0:21:47with this stuff - bright white lime wash.
0:21:50 > 0:21:54Lime wash is the most marvellous material,
0:21:54 > 0:21:59one of the great forgotten things from the Middle Ages.
0:21:59 > 0:22:04It absorbs carbon dioxide and hardens just like stone.
0:22:04 > 0:22:07The trouble is, to keep it bright and white,
0:22:07 > 0:22:09you have to do it every year.
0:22:16 > 0:22:20It's bad enough painting a little wall like this.
0:22:20 > 0:22:24Can you imagine what it was like painting a whole castle?
0:22:24 > 0:22:27It's just the question is, why bother?
0:22:29 > 0:22:32Modern weapons are all about stealth,
0:22:32 > 0:22:37but in an earlier age, this fortress was very much about broadcasting a message.
0:22:37 > 0:22:41The building wasn't hiding, it was standing out,
0:22:41 > 0:22:44a brutish display of English power.
0:22:44 > 0:22:47This was the castle in full glory,
0:22:47 > 0:22:50the shock and awe of the 13th century.
0:22:50 > 0:22:56Can you imagine what that castle would have looked like painted all white?
0:22:56 > 0:23:01A symbol of the conquest of Wales, but also a provocation.
0:23:04 > 0:23:08Just across Tremadog Bay, from the battlements of Harlech Castle,
0:23:08 > 0:23:13you can glimpse another, less menacing fortress.
0:23:20 > 0:23:23I'm on the Llyn peninsula at Criccieth.
0:23:25 > 0:23:31Mark Horton, over the water at Harlech, isn't the only one with a castle on this coast.
0:23:31 > 0:23:34There are plenty to go around.
0:23:34 > 0:23:38The original Criccieth Castle wasn't built by English Edward I,
0:23:38 > 0:23:40but by his opponents, the Welsh Princes,
0:23:40 > 0:23:43Llywelyn the Great and Llywelyn the Last.
0:23:43 > 0:23:45I think his name, Llywelyn the Last,
0:23:45 > 0:23:49tells you all you need to know about how things worked out.
0:23:49 > 0:23:54The Welsh, from their power base in the mountains of Gwynedd,
0:23:54 > 0:23:57rose up in a war of national independence in 1282.
0:23:57 > 0:24:01But they were fatally divided and Edward crushed them.
0:24:01 > 0:24:06Llywelyn was separated from his army and killed by the English at Cilmeri.
0:24:06 > 0:24:11Edward then took over this Welsh castle at Criccieth and remodelled it.
0:24:11 > 0:24:14But 100 or so years after defeat by Edward I,
0:24:14 > 0:24:16the Welsh were back for more.
0:24:16 > 0:24:18There was another great uprising in 1400,
0:24:18 > 0:24:21led by the charismatic Owain Glyndwr.
0:24:21 > 0:24:23Owain was a truly national leader,
0:24:23 > 0:24:26with powerful allies like the King of France.
0:24:27 > 0:24:31By 1403, much of Wales was under Owain's control.
0:24:31 > 0:24:36He even captured the mighty Harlech and held it for five years.
0:24:36 > 0:24:38At Criccieth he tore down much of the castle
0:24:38 > 0:24:41that the English had extended,
0:24:41 > 0:24:44a grand gesture that ultimately proved futile.
0:24:44 > 0:24:46The English struck back.
0:24:46 > 0:24:51Owain Glyndwr's revolt stuttered on, but he became a hunted man,
0:24:51 > 0:24:53a fugitive and a guerrilla,
0:24:53 > 0:24:56and nothing certain is known about him after 1412.
0:24:56 > 0:25:00He slipped away then into the shadow world of myth and legend,
0:25:00 > 0:25:01a so-called Son of Prophecy,
0:25:01 > 0:25:04who would return from his mountain hideout
0:25:04 > 0:25:07to free Wales in her hour of need.
0:25:08 > 0:25:12Owain's yet to return to claim Criccieth Castle.
0:25:12 > 0:25:16For now, it stands a silent sentinel,
0:25:16 > 0:25:18guarding the sainted lands beyond.
0:25:21 > 0:25:23Subtitles by Red Bee Media Ltd