This is when Egypt began the conquest of Lower Nubia. The Twelfth Dynasty of Egypt Pharaoh Senwosret I established forts at Ikkur, Quban, Aniba, Buhen, and Kor. The fort at Qubban protected gold mining operations along Wadi Allaqi and Wadi Gabgaba. The long history of Egyptian military activity in Lower Nubia may indicate that Kerma was perceived as a threat to Pharaonic Egypt at varying times. Principal Egyptian fortifications were built in the middle Nile Valley during the Middle Kingdom. These were to secure the Upper Egyptian border against raids from Kerma, and more than likely and to protect the valuable trade routes between the two regions. Both during the Middle and New Kingdoms, the resources Kerma possessed – gold, cattle, milk products, ebony, incense, ivory, etc. – were much coveted by Egypt. Its army were built around archers. Yet, Egyptian control weakened during the 13th Dynasty and 2nd Intermediate Period. This became the period of greatest development of Kerma and its greatest extent. Massive royal tombs were built in the city's necropolis, and included a large number of human sacrifices, and secondary burials. Two large tumuli include white quartzite cones. Kushite confrontations also occurred with Egypt in Lower Nubia. During its zenith, Kerma formed a partnership with the Hyksos and tried to crush Egypt. Discoveries in 2003 at the Governor of El Kab's Tomb (near Thebes) show that Kerma invaded deep into Egypt between 1575 and 1550 BC. It is believed that this was one of Egypt's most humiliating defeats, which later pharaohs had erased from the official historic records. Many royal statues and monuments were looted from Egypt and removed to Kerma, apparently as a gesture of triumph by Kerma's ruler. New Kingdom period Under Thutmose I, Egypt made several campaigns south, destroying Kerma. This eventually resulted in the Egyptian annexation of Nubia (Kerma/ Kush) c.1504 BC, and the establishment a southern frontier at Kurgus, south of the Fourth Cataract. After the conquest, Kerma culture was increasingly 'Egyptianized' yet rebellions continued for 220 years (till c.1300 BC). During the New Kingdom, Kerma/Kush nevertheless became a key province of the Egyptian Empire - economically, politically and spiritually. Indeed, major Pharonic ceremonies were held at Jebel Barkal near Napata, which included a large Amun temple. The New Kingdom of Egypt maintained control of Lower and Middle Nubia, with a Viceroy of Kush, or 'King's Son of Kush'. Egyptian settlements were