Short answers, pulled from the story.
Roman dominion stretched from the Iberian Peninsula to Egypt in 30 BC. The phrase Mare Nostrum began to describe the entire Mediterranean Sea during this period.
Italian nationalists used the term Mare Nostrum for colonial expansion during the Scramble for Africa of the 1880s. They called for establishing an Italian colonial empire and presented Tripolitania and Cyrenaica as new provinces of what became Italian Libya on a map in 1912.
In summer 1942, green areas on maps denoted territorial control by the Italian Navy while red zones showed where Allied forces held ground. Axis invasions of Albania, Greece, Yugoslavia and Egypt sought to extend control over the Sea before surrendering in September 1943.
The Italian government authorized Operation Mare Nostrum to rescue migrants from compromised boats leaving North Africa after the 2013 Lampedusa migrant shipwreck. A map shows eight corvettes assigned to patrol duties under this program to strengthen national systems for patrolling the Mediterranean Sea.
That event occurred in June 2012 at the University of Cagliari Faculty of Law in Sardinia. Organizers intended the phrase to embrace full diversity of Mediterranean cultures and focus on exchanges and cooperation among Mediterranean nations.