By Mike Collett-White

LONDON (Reuters) - An exhibition marking the 500th anniversary of Henry VIII's accession to the throne uses spectacular armour to highlight his love of sport and interest in warfare as well as the king's expanding waistline.

"Henry VIII: Dressed to Kill" opens at the Tower of London on April 3 and runs until January 17, 2010, and is one of a series of exhibitions planned across the country this year to celebrate the famous king's coronation in 1509 aged 17.

The show draws on the Royal Armouries collections and loans from museums abroad to build a picture of Henry's reign, which, through its emphasis on modern warfare and technology, arguably changed the course of history long after his death.

"Henry was at the forefront of fashion and at the forefront of artistic decoration," Thom Richardson, Keeper of Armour and Oriental Collections at the Royal Armouries, told Reuters.

"He was vain and incredibly wealthy, but he also wanted to present himself as a proper European monarch like Charles V or Maximilian ... and wanted the English army to be a proper Continental army.

"He was a great moderniser and a patron of technological change. Because of the British gunnery at the battle with the Spanish Armada we won, so you could say that because of his interest in technology we're not speaking Spanish today."

English and Spanish ships clashed in the waters between England and France in 1588, 41 years after Henry's death.

ARMOUR, ARMS AND FOOTBALL

On display in the famous White Tower building is the elaborately decorated "Silvered and Engraved" armour dating from 1515 and the Tonlet Armour made for the king in 1520.

The layered, skirt-style suit had to be prepared in only a few months for the Field of the Cloth of Gold tournament between the English and French courts, after the French changed the rules of the contest at the last minute.

Henry competed in the joust, wrestling, archery and foot combat with varying degrees of success, and fought on foot with "suche force that the fier sprang out of their armure."

The exhibition calculates Henry's changing body shape based on the size of the armour. At the age of 23, the king's waist was 88 cm and his chest 105.5 cm. By the age of 48, the portly monarch's waist had grown to 129.5 cm and his chest to 138 cm.

Among the exhibits is the earliest known soccer ball from the 16th century made of an inflatable pig's bladder covered in leather. Henry commissioned his own pair of soccer boots at a cost of four shillings, or 100 pounds in today's prices.

His love of sport was dangerous. In 1525, in pursuit of a hawk, he tried to pole vault over a ditch and landed head first in muddy water, only to be rescued by a footman.

Henry's jousting career ended when at 44 he "fell so heavily that everyone thought it was a miracle he was not killed."

He was equally occupied with building England's defences, spending the modern equivalent of one billion pounds in developing new weapons and arming and equipping his forces.

Among the innovations he embraced were gun shields that were probably used on Henry's warships and multi-barrelled canons.

Other highlights include the Wilton armour, possibly the king's last suit of armour made in about 1544, and the outlandish helmet given to Henry by Maximilian I in 1514.

The face on the metal mask appears to be a parody of Maximilian's own features, the pair of glasses and rams' horns may signal cuckoldry and a dew drop on the nose further suggests the emperor was laughing at himself.

(Editing by Paul Casciato)