From Byron's Don Juan (Canto The Tenth, XLIX):
While this high post of honour's in abeyance,
For one or two days, reader, we request
You'll mount with our young hero the conveyance
Which wafted him from Petersburgh: the best
Barouche, which had the glory to display once
The fair czarina's autocratic crest,
When, a new lphigene, she went to Tauris,
Was given to her favourite, and now bore his.
What is the meaning of the last line? It gravels me. I don't understand what's going on there.
The crest symbol was given to the favorite of Catherine the Great? So that he could display it on his vehicles? But what is "...and now bore his"? Now the barouche bore the coat of arms belonging to Don Juan's family?
I googled and found a footnote to "favorite", but that footnote does not explain the meaning of the line to me:
Transcript of screenshot:
 The empress went to the Crimea, accompanied by the Emperor Joseph, in the year — I forget which. — [The Prince de Ligne, who accompanied Catherine in her progress through her southern provinces, in 1787, gives the following particulars:—"We have been traversing, during several days, an immense tract of deserts formerly inhabited by hostile Tartar hordes, but recovered by the arms of her majesty, and at present ornamented from stage to stage with magnificent tents, where we are supplied with breakfast, collation, dinner, supper, and lodging; and our encampments decorated with all the pomp of Asiatic splendour, present a noble military spectacle. The empress has left, in each town, presents to the amount of 100,000 rubles. Each day of rest is marked by the gift of some diamonds, by balls, by fireworks, and by illuminations extending for leagues in every direction. During the last two months I have been daily employed in throwing money out of our carriage-windows, and have thus distributed the value of some millions of livres." Lettres et Pensèes. — E.
 When his lordship travelled to Pisa, "seven servants, five carriages, nine horses, a monkey, a bull-dog and mastiff, two cats, three peafowls, and some hens (I do not know whether I have classed them in order of rank), formed part of his live stock." Medwin. — E.