for bishops or abbots, their form is based on the idea of the clerics as shepherds for their flocks. Although their production ends c. 1200, they continued in use and were often refurbished and added to until the late medieval period. After the dissolution of the monasteries in the 12th and 13th centuries, the croziers were in danger of plunder from both Viking and Norman invaders. As large objects, they were difficult to hide, a reason why so many surviving examples show evidence of having been broken in two; reducing their length made them easier to hide in small spaces. A majority of the surviving extant croziers or fragments were held over the centuries by hereditary keepers (usually generations of a local family) until their re-discovered by antiquarians in the early 19th century. The croziers are often ornamented with interlace designs, geometric patterns and zoomorphic (portraying humans as non-human animals) figures. The animal designs in the earliest example, including the 9th century Prosperous Crozier, are depicted in a naturalistic manner, while many of the later examples, such as the c. 1100 Lismore Crozier, bear influence from both the Ringerike and lUrnes styles of Viking art. Some of the Ringerike style animals bear close resemblance to figures on the margins of ninth-century Celtic brooches. In craftmanship and ornamentation, the late 11th century Clonmacnoise Crozier is considered the finest of the fully intact example, followed in quality by the 11th century River Laune and Lismore Crozier. Late Medieval Over the course of the 12th century, the Viking port cities of Dublin, Waterford and Cork developed extensive trade links with Britain and the continent. This led to greater exposure to international styles and inevitably began the end of the Insular period of Irish art. The earlier style largely came to an end after the mid-12th century Church reform movement, the Norman invasion of 1169–1170 and the subsequent wide adoption of Romanesque art. According to Kelly, by the late Middle Ages, "much of the material on display [in the museum] illustrates lifestyles, trades and activities that were common to much of medieval Europe". This, through the Gothic and Renaissance periods Irish art was essentially a regional variation of wider European styles. The English colonisation of Ireland resulted the island having two separate identities through the last Middle Ages, each with their own language, laws and cultures, a fact that can be discerned from contemporary