In about 260 AD, the fall of the Agri Decumates territory north of the Rhine transformed today's Switzerland into a frontier land of the Empire. Repeated raids by the Alamanni tribes provoked the ruin of the Roman towns and economy, forcing the population to find shelter near Roman fortresses, like the Castrum Rauracense near Augusta Raurica. The Empire built another line of defense at the north border (the so-called Donau-Iller-Rhine-Limes), but at the end of the fourth century the increased Germanic pressure forced the Romans to abandon the linear defence concept, and the Swiss plateau was finally open to the settlement of German tribes.
What was the name of the concept used by the Roman Empire when building another line of defense at the north border?
the linear defence concept

Although John was the Count of Poitou and therefore the rightful feudal lord over the Lusignans, they could legitimately appeal John's actions in France to his own feudal lord, Philip. Hugh did exactly this in 1201 and Philip summoned John to attend court in Paris in 1202, citing the Le Goulet treaty to strengthen his case. John was unwilling to weaken his authority in western France in this way. He argued that he need not attend Philip's court because of his special status as the Duke of Normandy, who was exempt by feudal tradition from being called to the French court. Philip argued that he was summoning John not as the Duke of Normandy, but as the Count of Poitou, which carried no such special status. When John still refused to come, Philip declared John in breach of his feudal responsibilities, reassigned all of John's lands that fell under the French crown to Arthur – with the exception of Normandy, which he took back for himself – and began a fresh war against John.
When did Philip summon John to attend court?
1202

Jerusalem with its many holy places probably had the highest concentration of mosaic-covered churches but very few of them survived the subsequent waves of destructions. The present remains do not do justice to the original richness of the city. The most important is the so-called "Armenian Mosaic" which was discovered in 1894 on the Street of the Prophets near Damascus Gate. It depicts a vine with many branches and grape clusters, which springs from a vase. Populating the vine's branches are peacocks, ducks, storks, pigeons, an eagle, a partridge, and a parrot in a cage. The inscription reads: "For the memory and salvation of all those Armenians whose name the Lord knows." Beneath a corner of the mosaic is a small, natural cave which contained human bones dating to the 5th or 6th centuries. The symbolism of the mosaic and the presence of the burial cave indicates that the room was used as a mortuary chapel.
Where was the Armenian Mosaic found in Jerusalem?
near Damascus Gate