y History, Wiltshire_; _History of Devizes_ (Devizes,
1859).

DEVOLUTION, WAR OF (1667-68), the name applied to the war which arose
out of Louis XIV.'s claims to certain Spanish territories in right of
his wife Maria Theresa, upon whom the ownership was alleged to have
"devolved." (See, for the military operations, DUTCH WARS.) The war was
ended by the treaty of Aix-la-Chapelle in 1668.

DEVON, EARLS OF. From the family of De Redvers (De Ripuariis; Riviers),
who had been earls of Devon from about 1100, this title passed to Hugh
de Courtenay (c. 1275-1340), the representative of a prominent family in
the county (see Gibbon's "digression" in chap. lxi. of the _Decline and
Fall_, ed. Bury), but was subsequently forfeited by Thomas Courtenay
(1432-1462), a Lancastrian who was beheaded after the battle of Towton.
It was revived in 1485 in favour of Edward Courtenay (d. 1509), whose
son Sir William (d. 1511) married Catherine, daughter of Edward IV. Too
great proximity to the throne led to his attainder, but his son Henry
(c. 1498-1539) was restored in blood in 1517 as earl of Devon, and in
1525 was created marquess of Exeter; his second wife was a daughter of
William Blount, 4th Lord Mountjoy. The title again suffered forfeiture
on Henry's execution, but in 1553 it was recreated for his son Edward
(1526-1556). At the latter's death it became dormant in the Courtenay
family, till in 1831 a claim by a collateral branch was allowed by the
House of Lords, and the earldom of Devon was restored to the peerage,
still being held by the head of the Courtenays. The earlier earls of
Devon were referred to occasionally as earls of Devonshire, but the
former variant has prevailed, and the latter is now solely used for the
earldom and dukedom held by the Cavendishes (see DEVONSHIRE, EARLS AND
DUKES OF, and also the article COURTENAY).

DEVONIAN SYSTEM, in geology, the name applied to series of stratified
fossiliferous and igneous rocks that were formed during the Devonian
period, that is, in the interval of time between the close of the
Silurian period and the beginning of the Carboniferous; it includes the
marine Devonian and an estuarine Old Red Sandstone series of strata. The
name "Devonian" was introduced in 1829 by Sir R. Murchison and A.
Sedgwick to describe the older rocks of Cornwall and Devon which W.
Lonsdale had shown, from an examination of the fossils, to be
intermediate between the Silurian and Carboniferous. The s