quality:correction, linguistic:paraphrasing
Military

Apart from permanent garrisons at Berwick, Calais, and Carlisle, England's standing army numbered only a few hundred men. This was increased only slightly by Henry. Henry's invasion force of 1513, some 30,000 men, was composed of billmen and longbowmen, at a time when the other European nations were moving to hand guns and pikemen but the difference in capability was at this stage not significant, and Henry's forces had new armour and weaponry. They were also supported by battlefield artillery and the war wagon, relatively new innovations, and several large and expensive siege guns. The invasion force of 1544 was similarly well-equipped and organised, although command on the battlefield was laid with the dukes of Suffolk and Norfolk, which in the latter case produced disastrous results at Montreuil.

Henry's break with Rome incurred the threat of a large-scale French or Spanish invasion. To guard against this, in 1538 he began to build a chain of expensive, state-of-the-art defences along Britain's southern and eastern coasts, from Kent to Cornwall, largely built of material gained from the demolition of the monasteries. These were known as Henry VIII's Device Forts. He also strengthened existing coastal defence fortresses such as Dover Castle and, at Dover, Moat Bulwark and Archcliffe Fort, which he visited for a few months to supervise. Wolsey had many years before conducted the censuses required for an overhaul of the system of militia, but no reform resulted. In 1538–39, Cromwell overhauled the shire musters, but his work mainly served to demonstrate how inadequate they were in organisation. The building works, including that at Berwick, along with the reform of the militias and musters, were eventually finished under Queen Mary.

Henry is traditionally cited as one of the founders of the Royal Navy. Technologically, Henry invested in large cannon for his warships, an idea that had taken hold in other countries, to replace the smaller serpentines in use. He also flirted with designing ships personally. His contribution to larger vessels, if any, is unknown, but it is believed that he influenced the design of rowbarges and similar galleys. Henry was also responsible for the creation of a permanent navy, with the supporting anchorages and dockyards. Tactically, Henry's reign saw the Navy move away from boarding tactics to employ gunnery instead. The Tudor navy was enlarged from seven ships to up to 50 (the Mary Rose among them), and Henry was responsible for the establishment of the "council for marine causes" to oversee the maintenance and operation of the Navy, becoming the basis for the later Admiralty.