I've often wondered how landings like these occurred. From as early as the Viking Raids to the start of the 16th century.
In the movie Robin Hood (2010) at the final battle, you see a French invasion force rowing to the coastline in landing craft eerily similar to landing craft used during the Normandy landings. Obviously this is a load of Hollywood rubbish (I could be wrong), but I struggle to fathom how it was done. Few sources I've read say that the ships approached from the stern, lowering ramps, or having some kind of door that allows the troops or cavalry to get onto the beach, looking at some Medieval ships though I can't really see an area to place said ramps/doors. I've also read that barges were used to unload Cavalry and artillery pieces.
This question can also be applied to landings that occurred in ancient times.
I've been doing some research on naval logistics, so I think I can probably give you a good enough answer.
The ships with ramps were almost exclusively to be found in the Mediterranean. They seem to have had a Byzantine origin, either in 960 AD or just before. Their first recorded usage was during Nicephorus Phocas' invasion of Crete. He brought the horse transports up to the shore and offloaded his cavalry already armed and mounted, much to the surprise of the Muslim defenders^1. Whether the ships were decked and the horses unloaded through a hatch, or whether the ships were open decked and the ramps attached to the gunwales isn't clear from the text.
At least by 1174 there were galleys with rear ramps^2. A contract drawn up in 1249 between Louis IX's agents and the Genoese in 1246 gives us an idea of what they would have looked like and how many horses they could have carried. They were 35.71m in length, 3.48m wide at the waist on the horse deck, and the headroom was 2.25m. They had specially constructed bluff sterns, with two doors for embarkation and landing, and were to transport 20 horses^3. The statutes of Marseilles of 1253 specified that the width of each space allotted a horse on a Crusader transport should be 0.76m^4. Interestingly, the stall width and the head room didn't change in 650 years^5. Anyway, Pryor proposes that, as the galleys (taradia) weren't wide enough for two rows of horses, the horses would have been loaded crosswise across the centre of the ship, alternately facing left and right. The knights could therefore be unloaded through both doors, ten to a door^6.
Unlike round ships, the oar powered galleys could be rowed to the beach. This allowed whoever used them to have a cavalry force almost immediately available after landing, and seem to have been employed by both Arab and Western commanders^7.
There were a couple of ways a force could be unloaded. They could, for instance, transfer into small ships boats, as Jean de Joinville did in the 7th Crusade^8. The boats could not always come in right to the shore, and so the men-at-arms might need to jump into the water and wade to shore^9. While some galleys might be able to drive up onto shore so that their combatants could land on dry land^10, it seems that a good proportion could not, and any landing would still require a wade through water^11.
Once a beach head had been secured, temporary docks and ramps could be made using hurdles, gangplanks and pre-built bridges, and these could be used to unload further horses and bulk supplies, like barrels of ale or flour, or grain^12. Some of the larger ships, which could carry upwards of a hundred horses and several hundred men, likely required a proper dock, however.
^1 John H. Pryor (1982) TRANSPORTATION OF HORSES BY SEA DURING THE ERA OF THE CRUSADES: EIGHTH CENTURY TO 1285 A.D.: Part I: To c 1225, The Mariner's Mirror, 68:1, 10
^2 ibid, p19
^3 John H. Pryor (1982) TRANSPORTATION OF HORSES BY SEA DURING THE ERA OF THE CRUSADES: EIGHTH CENTURY TO 1285 AD, The Mariner's Mirror, 68:2, 109-110
^4 ibid
^5 M. Horace Hayes (1902), Horses on board ship: a guide to their health, Hurst and Blackett, p119, 125
^6 John H. Pryor (1982) TRANSPORTATION OF HORSES BY SEA DURING THE ERA OF THE CRUSADES: EIGHTH CENTURY TO 1285 AD, The Mariner's Mirror, 68:2, 109
^7 ibid; John H. Pryor (1982) TRANSPORTATION OF HORSES BY SEA DURING THE ERA OF THE CRUSADES: EIGHTH CENTURY TO 1285 A.D.: Part I: To c 1225, The Mariner's Mirror, 68:19
^8 Joinville and Villehardoun: Chronicles of the Crusades, tr. Smith, Caroline (2008), Penguin Classics, p184
^9 ibid, p185
^10 ibid
^11 Anonymous (2001), Itinerary of Richard I and others to the Holy Land, p24, Cambridge http://www.yorku.ca/inpar/richard_of_holy_trinity.pdf (accessed 26/12/16)
^12 Lambert, Craig L. (2011), Shipping the Medieval Military, p94-95
Follow-up question, any examples of movies or television shows that have a realistic depiction of a medieval (or earlier) amphibious assault, assuming you agree with OP that Robin Hood's scene was Hollywood rubbish?