Final answer:
William Hogarth was the first Western artist to work in series, exemplified by his notable sequence 'A Rake's Progress' from the 1730s.
Step-by-step explanation:
The first Western artist known for working in series is William Hogarth. Hogarth gained notoriety for his satirical and sequential art pieces, with one of his most famous being 'A Rake's Progress', which is a series of eight paintings completed in the 1730s. This sequence of paintings depicts the decline and fall of Tom Rakewell, the protagonist, and serves as social commentary on the excesses and moral decay of the time. The concept of creating multiple works of art that relate to a single theme or tell a cohesive story was innovative and helped to establish Hogarth as a significant figure in art history.