Illustrations from the:

Lorvão Beatus
Commentary on the Apocalypse by Beatus of Liébana,
Portugal (Lorvão?), copy of 1189
Folio 115r. The Sixth Seal

A larger image of The Sixth Seal, Lorvão Beatus. Commentary on the Apocalypse by Beatus of Liébana, copy of 1189. Ms 44.

And I saw when he opened the sixth seal, and there was a great earthquake, and the sun became black as sackcloth of hair, and the whole moon became like blood". (Rev. 6:12)

The iconographic element of the rider has no parallel in this thematic representation in the universe of Beatos.