The introduction of Buddhism is assigned to the year 638 A.D., one of the first authentic dates in the native records. The ancient city of Labong had already been founded (575), and other settlements now followed rapidly, always in the direction of the south, according as the Shan race steadily advanced towards the seaboard, driving before them or mingling with Khmers, Lawas, Karens, and other aborigines, some now extinct, some still surviving on the wooded uplands and plateaux encircling the Menam valley. Ayuthia, the great centre of national life in later times, dates only from the year 1350, when the empire had received its greatest expansion, comprising the whole of Camboja, Pegu, Tenasserim, and the Malay Peninsula, and extending its conquering arms across the inland waters as far as Java[460]. Then followed the disastrous wars with Burma, which twice captured and finally destroyed Ayuthia (1767), now a picturesque elephant-park visited by tourists from the present capital, Bangkok, founded in 1772 a little lower down the Menam. But the elements of decay existed from the first in the institution of slavery or serfdom, which was not restricted to a particular class, as in other lands, but, before the modern reforms, extended in principle to all the kings' subjects in mockery declared "Freemen" by the founders of the monarchy. This, however, may be regarded as perhaps little more than a legal fiction, for at all times class distinctions were really recognised, comprising the members of the royal family--a somewhat numerous group--the nobles named by the king, the _leks_ or vassals, and the people, these latter being again subdivided into three sections, those liable to taxation, those subject to forced labour, and the slaves proper. But so little developed was the sentiment of personal dignity and freedom, that anybody from the highest noble to the humblest citizen might at any moment lapse into the lowest category. Like most Mongoloid peoples, the Siamese are incurable gamblers, and formerly it was an everyday occurrence for a freeman to stake all his goods and chattels, wives, children, and self, on the hazard of the die.