The heavily armed carrack, first developed in Portugal for either trade or war in the Atlantic Ocean, was the precursor of the ship of the line. Other maritime European states quickly adopted it in the late 15th and early 16th centuries. These vessels were developed by fusing aspects of the cog of the North Sea and galley of the Mediterranean Sea. The cogs, which traded in the North Sea, in the Baltic Sea and along the Atlantic coasts, had an advantage over galleys in battle because they had raised platforms called “castles” at bow and stern that archers could occupy to fire down on enemy ships or even to drop heavy weights from. At the bow, for instance, the castle was called the forecastle (usually contracted as fo’c’sle or fo’c’s’le, and pronounced FOHK-səl). Over time these castles became higher and larger, and eventually were built into the structure of the ship, increasing overall strength. This aspect of the cog remained in the newer-style carrack designs and proved its worth in battles like that at Diu in 1509.

The Mary Rose was an early 16th-century English carrack or “great ship”. She was heavily armed with 78 guns and 91 after an upgrade in the 1530s. Built in Portsmouth in 1510–1512, she was one of the earliest purpose-built men-of-war in the English navy. She was over 500 tons burthen and had a keel of over 32 metres (105 ft) and a crew of over 200 sailors, composed of 185 soldiers and 30 gunners. Although the pride of the English fleet, she accidentally sank during the Battle of the Solent, 19 July 1545.

Henri Grâce à Dieu (English: “Henry Grace of God”), nicknamed “Great Harry”, was another early English carrack. Contemporary with Mary Rose, Henri Grâce à Dieu was 50 metres (160 ft) long, measuring 1,000–1,500 tons burthen and having a complement of 700–1,000. It is said[by whom?] that she was ordered by Henry VIII in response to the Scottish ship Michael, launched in 1511. She was originally built at Woolwich Dockyard from 1512 to 1514 and was one of the first vessels to feature gunports and had twenty of the new heavy bronze cannon, allowing for a broadside. In all, she mounted 43 heavy guns and 141 light guns. She was the first English two-decker, and when launched she was the largest and most powerful warship in Europe, but she saw little action. She was present at the Battle of the Solent against Francis I of France in 1545 (in which Mary Rose sank) but appears to have been more of a diplomatic vessel, sailing on occasion with sails of gold cloth. Indeed, the great ships were almost as well known for their ornamental design (some ships, like the Vasa, were gilded on their stern scrollwork) as they were for the power they possessed.

Carracks fitted for war carried large-calibre guns aboard. Because of their higher freeboard and greater load-bearing ability, this type of vessel was better suited than the galley to wield gunpowder weapons. Because of their development for conditions in the Atlantic, these ships were more weatherly than galleys and better suited to open waters. The lack of oars meant that large crews were unnecessary, making long journeys more feasible. Their disadvantage was that they were entirely reliant on the wind for mobility. Galleys could still overwhelm great ships, especially when there was little wind and they had a numerical advantage, but as great ships increased in size, galleys became less and less useful.

Another detriment was the high forecastle, which interfered with the sailing qualities of the ship; the bow would be forced low into the water while sailing before the wind. But as guns were introduced and gunfire replaced boarding as the primary means of naval combat during the 16th century, the medieval forecastle was no longer needed, and later ships such as the galleon had only a low, one-deck-high forecastle. By the time of the 1637 launching of England’s Sovereign of the Seas, the forecastle had disappeared altogether.