After the submission of those cities to Alexander the Great in 333 b.c. the globe and crescent seems to have been exchanged for a cruciform standard similar to that shown in the left hand of the goddess Astarte in the coin of 87 b.c. depicted in [Plate II], fig. 4. This cruciform standard was probably adopted by Alexander from the Athenians, the most prominent naval power of Greece, among whom it seems to have been an object of great significance[14]. On two great amphorae awarded to the victors in the Panathenaic games of 336-5 b.c., now in the British Museum, it is represented in a manner which can leave no doubt as to its symbolic importance. On one of them Athene holds in her hand a long cruciform staff, the head of which is expanded in ovoid form. On the other amphora the goddess has by her side a short column which is surmounted by a winged Victory (Nike) holding in her left hand a similar standard, and in her right the aphlaston of a galley. Unfortunately for our purpose, the Athenians did not represent ships upon their coinage, but similar standards are seen in the hand of the nymph Histiaea upon the coins of the Euboean town of that name, dated circa 313-265 b.c., two of which are represented in [Plate II], figs. 7 and 8. Many other instances, too numerous to detail, will be found upon later Greek coins. In these the crosses are not all of the same design, and Prof. Babelon has collected examples of thirty-six forms, all more or less different, from the plain cross to a more elaborate form in which the head terminates in a ball and two small winged figures of Victory kneel at the ends of the arms. Some of these forms are decorated with narrow streamers; in many of them the cross-piece is not at right angles to the staff, but it is possible that this may be due to an attempt at perspective. One other instance deserves mention: the excavations on the site of the important city of Pergamum in Asia Minor, once the capital of the kingdom of Pergamus, and afterwards that of the Roman province of Asia, have brought to light the bas-reliefs which decorated the balustrade of the Portico of Athene Polias. On this bas-relief, which, in the opinion of M. Collignon[15], alludes to naval victories under Attalus (241-197 b.c.) or Eumenes II (197-159), the cruciform standard is twice represented in highly ornate forms terminating in pine cones at the head; in each case it is accompanied with the aphlasta and beaks of galleys.
A careful study of all the examples leads to the conclusion that this globe and crescent, or cruciform, standard was the symbol of naval authority, the prototype in fact of the Admiral's flag. The name of this standard is not specifically stated, but there can be no doubt that it is the semeion (σημεῖον) frequently referred to by Greek authors in describing naval actions. That the semeion was a solid object we know from the fact that it was raised aloft in giving signals[16]. There is evidence that semeia were of various forms and that these forms were distinctive of the nationality of the ship. Of Artemisia, queen of Halicarnassus, who accompanied Xerxes in his expedition against Greece and fought on the Persian side at the Battle of Salamis (480 b.c.), Polyaenus, in his Strategemata, relates that she had two semeia, one of "barbarian" form, the other Greek. When she was pursuing a Greek ship she raised aloft the barbarian standard[17], but when fleeing before a Greek ship she raised the Greek standard, so that her pursuer took her ship for Greek and kept off from it. The "barbarian" standard used by Artemisia was probably the globe and crescent above referred to, for Sidon supplied Xerxes with the best of his ships, and it was in Sidonian ships that Xerxes himself was wont to embark[18]. It seems, on the other hand, probable that a cruciform standard was in common use by all the Greek states at an early period, for Polyaenus relates that Chabrias, the Athenian general, just before his action off Naxos in 376 with the Lacedaemonian fleet under Pollis, ordered his subordinate commanders to remove the semeia from their ships and to keep in mind, in the ensuing conflict, that all ships bearing such signs were enemies[19].
The flag was evidently unknown to the early Greeks; it is never mentioned by Homer, and indeed there is no equivalent word in the language of the classical period, yet at the time when we first meet with the standard on the Phoenician coins flags were in common use by the Chinese. The Chinese classics on the art of war known as the Sun Tzu and Wu Tzu, written in the fifth century b.c., make frequent reference to them. They played a very important part in marshalling the army and inspiriting the soldiers, and the correct moment to strike the enemy was judged by the disorder of their flags. According to Wu, the Chinese flags contained various animal emblems.
The origin of the flag in European waters may however be dated from the end of the fifth century b.c., when a primitive form was, if later writers[20] are a safe guide, in use in the Athenian navy. This was the "purple garment" or "Phoinikis[21]," used as a signal for combat or as the sign of the Admiral's ship. Possibly the use of this emblem may have been imitated from the Phoenicians. It may, on the other hand, have originated independently, from a necessity of rendering the cruciform standard more conspicuous in action. There is not sufficient evidence to decide this point, but it is significant that the vexillum in use among the Romans at a somewhat later date shows traces of a similar origin.
The military standard or signum of the Romans consisted of a lance with silver-plated shaft with a cross-piece at the top, from which in some instances a small vexillum was suspended. From the ends of this cross-piece, whether it held a vexillum or not, hung ribbons with silver ivy leaves at the ends. Below were a number of discs, which are believed to represent the honours conferred upon the Legion to which the signum belonged[22]. Below these again was a crescent, as a charm against ill-fortune. In the signa of the Praetorian guard the discs were replaced by crowns alternating with medallion portraits of the imperial house. These signa were used as company ensigns to facilitate the tactical movements of the Legion. The principal standard of the Legion, answering to the Regimental Colours, was the aquila or eagle. Pliny the Elder[23] informs us that
Caius Marius in his second consulship (b.c. 103) assigned the eagle exclusively to the Roman Legions. Before that period it had only held the first rank, there being four others as well, the wolf, the minotaur, the horse and the wild boar, each of which preceded a single division. Some few years before his time it had begun to be the custom to carry the eagle only into battle, the other standards being left behind in camp. Marius however abolished the rest of them entirely.
The vexillum consisted of a square piece of material, usually red or purple but sometimes white or blue, hung by the top edge (or sometimes its two top corners only) from a cross-piece at the head of a lance and heavily fringed along its bottom edge. The peculiar method of attachment at the corners, which caused it to hang in heavy folds instead of straight down, would seem to indicate an origin similar to that of the Greek "Phoinikis." This was the standard appropriated to the cavalry and to the special detachments of infantry, and it is said to be the oldest of the Roman military standards. It hung before the General's tent and was used in giving the signal to prepare for battle[24]. From its use in this connection it naturally became the sign of a commander of a fleet of ships[25] and was used in giving the signal for fleet actions.
Flavius Vegetius[26], writing at the close of the fourth century a.d., distinguishes six kinds of military insignia, viz.: aquila, draco, vexillum, flammula, tufa and pinna. The Draco or dragon had been borrowed from the Parthians after the death of Trajan. It took the form of a dragon fixed upon a lance with gaping jaws of silver. The body was of coloured silk, and when the wind blew down the open jaws the body was inflated. The Flammula (little flame) was an elongated flag attached to the staff at the side, split throughout its length so as to form two narrow streamers. The Tufa seems, from the name, to have been some form of tuft[27] or helmet-crest, but the exact form is not known. It is of interest as having been adopted in Britain under the name Tuuf[28]. Pinnae was the name given to the side wings of the soldiers' helmets, apparently formed of feathers. The precise form of the pinna standard is not known, but it is probable that the fan-shaped feather standards which are displayed at the coronation of the pope are a survival of this, or the preceding form.
Until the end of the Roman Empire the standard was used at sea only for signalling purposes or to mark the ship in which the leader was embarked. Thus in the action off Marseilles in b.c. 49, in which Caesar's fleet under the command of Brutus engaged the Massilian fleet which was fighting on the side of Pompey, the ship in which Brutus was embarked was quickly recognised by the leader's standard, and narrowly escaped being rammed by two triremes from opposite sides[29].
There are frequent references to this standard in classical writers and it is often depicted in reliefs or on coins. From these it is clear that its position was on the starboard quarter of the ship, at the leader's right hand; it was raised there in going into action, and its removal was a sign of disaster or retreat. It would seem that it was also removed if the fleet was about to be engaged by superior forces, presumably in order that the enemy might not concentrate against the leader's ship. Thus in b.c. 36 Octavian, when expecting an attack at sea by Pompey, embarked in a liburnian and sailed round the fleet exhorting his men to have courage. When he had done this he lowered his standard "as is the custom in times of very great danger[30]."