Radio Times Prize Crossword 2 Friday January 11Th 2019

[Ancient]

Happy New Year to all of you!!
Stuck on a few in this one - all help greatly appreciated as always.

5d: Dance round singular Egyptian god to strait (9) ?o???o???; 13d: Vitamin-filled support on eastern flower (9) ?o?u?????; 14d: Counter a birth plan with bread from Cardiff (4,5) ?a?a,?????;
20d: Prince leaving Switzerland for French city (5) ?r?e?;

11a: Increase in rank,as one in pack? (6); 21a: Peninsula of cold region with no leader (6) ?????a;
23a: Shorebird's speed over water (4);

[kettledrum]

23a knot

[elliemay1]

23 knot

[JJ109]

23 Knot

[margarettom]

11. Iberia
Siberia no S

[elliemay1]

21 (S) Iberia

[Baldric]

5 BOSPHORUS
13 COLUMBINE
14 BARA BIRTH
20 ARLES

[elliemay1]

14 Bar a Brith

[kettledrum]

13d Columbine ... B1 in column + E

[bookbinder]

20d (ch) arles

[Baldric]

11 LUPINE
21 IBERIA
23 KNOT

[Ancient]

Thank you all so much for your speedy solutions; I'm never sure about awarding a Best Answer but I was grateful for getting the explanation of Columbine so I did it that way!
I have no idea how you arrived at Bosphorus Baldric xxx

[Mamyalynne]

Bop round S(ingular) + Horus

[Baldric]

Crossing letters and a good Spellcheck.