y have
either some commercial or semi-political union with one or another of
their neighbors. The little independent principality of Liechtenstein,
wedged in between Switzerland and the Tyrol, is included in the customs
union of Austro-Hungary. The small, independent duchy of Luxemburg,
which has been attached in turn to all the great states which have grown
up along its borders, is included in the _Zollverein_ of Germany. The
republic of Andorra, far up in a lofty valley of the Pyrenees, which has
maintained its freedom for a thousand years, acknowledges certain rights
of suzerainty exercised by France and the Spanish bishopric of
Urgel.[391]

[Sidenote: Guardians of the marches.]

Oftentimes a state gains by recognizing this freedom-loving spirit of
the frontier, and by turning it to account for national defence along an
exposed boundary. In consequence of the long wars between Scotland and
England, to the Scotch barons having estates near the Border were given
the Wardenships of the Marches, offices of great power and dignity; and
their clans, accustomed only to the imperfect military organization
demanded by the irregular but persistent hostilities of the time and
place, developed a lawless spirit. Prohibited from agriculture by their
exposed location, they left their fields waste, and lived by pillage and
cattle-lifting from their English and even their Scotch neighbors. The
valor of these southern clans, these "reivers of the Border," was the
bulwark of Scotland against the English, but their mutinous spirit
resisted the authority of the king and led them often to erect
semi-independent principalities.[392]

[Sidenote: Border nomads as frontier police.]

China has fringed her western boundaries with quasi-independent tribes
whose autonomy is assured and whose love of freedom is a guarantee of
guerilla warfare against any invader from Central Asia. The Mantze
tribes in the mountain borders of Sze-Chuan province have their own
rulers and customs, and only pay tribute to China.[393] The highlands of
Kansu are sprinkled with such independent tribes. Sometimes a definite
bargain is entered into--a self-governing military organization and a
yearly sum of money in return for defence of the frontier. The Mongol
tribes of the Charkar country or "Borderland" just outside the Great
Wall northwest of Pekin constitute a paid army of the Emperor to guard
the frontier against the Khalkhas of northern Mongolia, the tribe of