Solution to Tough Cryptic no.4  by Ravel

Across: Catherine (Howard) Louis (Armstrong) Aneurin (Bevan) 10 Isadora (Duncan) 11 Rocky (Marciano) 12 Aristotle (Onassis) 13 Wallis (Simpson) 14 Florence (Nightingale) 17 Theodore (Roosevelt) 19 Stuart (Little) 21 Siegfried (Sassoon) 24 Irene (Handl) 26 Antonia Fraser) 27 Orville (Wright) 28 Doris (Lessing) 29 Engelbert (Humperdinck)

Down: Chair Tiercel Early bird Ionia Eligible Leapt Unoften Stage left 13 Withstand 15 Retrieval 16 Irritate 18 Elector 20 Areolae 22 Funds 23 Droog 25 Event.