Perpendicular was the prevailing style of Late Gothic architecture in England from the 14th to the 17th century. As the name suggests, a notable characteristic is the emphasis on strong vertical lines, seen especially in window tracery and wall panelling. The perpendicular style is also characterized by large expanses of stained glass and increasingly complex vaults, including fan and lierne vaults. Web resources here and here.

St. George’s Chapel, Windsor Castle, England. 14th c.