Leaf from a finely illuminated Book of Hours, in Latin, manuscript on parchment

Leaf from a finely illuminated Book of Hours, in Latin, manuscript on parchment [England (perhaps London or Oxford), fifteenth century (probably 1410s or 1420s)]Single leaf, with large initial (near half page in height) 'D' ("Deus in adiutorium ...", reading for Nones from Hours of the Cross) in blue with white penwork, enclosing fleshy and bulbous acanthus leaves on burnished gold grounds, further acanthus leaf sprays terminating in coloured foliage and gold bezants in three margins, initial letter of the word 'Deus' enclosing a tiny dog's face poking out its tongue, two large illuminated initials in blue and dark rose-pink grounds heightened with white penwork, smaller initials in blue or liquid gold with contrasting penwork surrounds, red rubrics, capitals touched in red, 14 lines in two sizes of a fine English Gothic bookhand, slight discolouration in places from surface dirt adhering to rough surface of parchment, else fine condition, 180 by 126mm.The simplicity of the decoration here, with mirrored leaves above and below simple foliage strands, shaded with heavy white strokes, points to English illumination in the opening decades of the fifteenth century (see K.L. Scott, Dated & Datable English Manuscript Borders, 2002, pp. 28-35). The trumpet-like flowers and curled leaves decorated with lines of tiny white dots indicate a date in the 1410s or 1420s (ibid. pp. 42-43, recording a London or Westminster production of 1410-13; and pp. 52-53, with an Oxford product of 1429).