'Czech neck' refers to a method of cravat-knotting popularised by Byron and his contemporaries whilst on the Grand Tour. It was soon found that the bow knots favoured by the London set were ill-adapted to the needs of the stylish traveller - not only was overheating common on the road, but there were also several accidents linked to the neckwear.
After the tragic death of Lord de Quincelly-Popham of Barnes in a cravat-tangling incident in a Venetian brothel, young men began to tie their cravats in a tidier fashion that left fewer ends flapping and allowed for improved aeration.
The look became popular as 'Czech neck'. It is sometimes said that this otherwise unexplained title derives from a passing comment made by Percy Bysshe Shelley: "Check his neck, that cravat is sick!"
"In this portrait, Sir Robert Eggerston-Jolly proclaims his social status and European 'education' with the choice of the Czech neck"