Each is designed to commemorate someone who was a worshipper in this Church or in some way connected with it. Thus Pope Adrian IV is commemorated because he granted to the Abbey of Westminster the grounds on which the Church stood, and Bartholomew Nutt because he ferried the faithful across the river to church before there were any bridges. Some bear the Coat of Arms others, an illustration of an incident in the life, or foible in the character, of the person commemorated.

There is a catalogue prepared by NADFAS (now called the Arts Society) that has a photo, description, name of designer and embroiderer for each kneeler, which may be consulted.

You can read the brochure

Kneelers (cushions to kneel on) with the names and dates of people embroidered on them
Kneelers (cushions to kneel on) with intricate stitching of flowers and words.
The Queen mother admiring the kneelers in the Royal Hospital, Chelsea