How did aisling poems become popular in Irish literature?

In Irish literature, the aisling (a term meaning "vision" or "description of a vision") became a popular poetic genre during the 18th century.1

The rise of the aisling was driven by its utility as a vehicle for political expression. It served as a medium for poets to voice support for the exiled Roman Catholic king James II and to advocate for the restoration of the Stuart line to the throne. The genre was notably popularized by the poet Aodhagán Ó Rathoille, whose works helped establish the form within the broader tradition of Irish song meters that emerged following the decline of the professional bardic order.12

While the aisling became a significant literary convention, it was not without its critics; by the late 18th century, Brian Merriman’s famous comic poem, The Midnight Court, famously satirized the aisling tradition while critiquing contemporary social and sexual conventions.2