Blaise? (anag) (6)

Megalithic burial mound; tumulus (6)

Ship used in the quest for the Golden Fleece (4)

Underground alcoved tunnel for burying the dead (8)

Catch-22, perhaps (7)

Overcome completely; take by surprise (5,3,3)

Austrian composer (1824-96) of ten symphonies and four masses (5,8)

In England and Wales, the Crown's nominal chief executive in a county (7)

Pertaining to ancient Greece and Classical Greek culture (8)

Site of the Taj Mahal (4)

Carefree; cheerful (6)

China clay (6)

Caesar (54-68 AD), infamous purger of early Christians (4)

Allocation; apportionment (5,2,3,4)

Diminish; slacken (5)

See 15 Across

Of galactic proportions (6)

In the recent past (2,2,4)

See 3

Tease; irritate (6)

See 13 Across

Tack on; take over (5)

Long period of years; longest division of geological time (4)