It has been said that the term "Jack" is derived from the name of the sovereign James I. (_Jacques_), in whose reign it was constructed. This is the legend at the Admiralty, but it is of doubtful authority. The Oxford Glossary says there is not a shadow of evidence for it, and traces the word to the surcoat worn of old by the soldiery called a _jacque_--whence jacket. But this also is doubtful. The Union, or junction of the three crosses, is used in other cases in the royal navy, and also in the merchant service, not by itself, but in certain combinations. THE ENSIGN. The flag under which all our ships now sail is the Ensign. In early times every chieftain or knight, whether serving in the field or on board ship, had his own distinguishing flag, and if several knights were embarked in one ship, the ship carried the flags of them all. In one of the illuminations of the reign of Henry VI., the sides of a ship are covered with shields, and in other examples armorial devices are even shown painted on the sails. When engaged in any active service, a ship would carry also the flag of the leader or admiral, and, in addition to this, the emblem of some patron saint, depending in this on the caprice or superstition of the owner. Besides these a ship usually bore the flag of her port--a usage which, so far as merchant ships are concerned, still holds among us in the practice of carrying what are known as "house flags," though now strictly subordinated to that of carrying the national ensign. With ships of other countries the usage continued till comparatively lately. In France, down to the Revolution, merchant ships flew the flag of their port more commonly than the flag of France; as for instance, of Marseilles, white with a blue cross; or of Dunkirk, barry of six argent and azure, with the alternative of the old English white ensign, white with a small St. George's cross in the upper corner next the hoist, derived from the English sovereignty in the seventeenth century.[39] In the same way in the Baltic: in the Netherlands almost every port had its own flag, and the free towns of Germany till quite recently followed the same practice. It was the same in England in early times--a sailor being more a sailor of his port than of his country. [39] Laughton's _Heraldry of the Sea_. Now, as a rule, the ships of all countries sail under their national colours. With us the flag under which all our ships sail is the Ensign, of which there are three--the white, the blue, and the red. It is a large flag of one of the colours named, with the Union in a square or canton at the upper part of the hoist. I may explain that the portion of a flag next the staff or rope from which it is flown is called the hoist, the next is called the centre, and the outer portion the fly. Besides the Union in the canton, the white ensign has the St. George's cross extending over the whole field.