Kuroda Nagamasa  was a daimyō during the late Azuchi-Momoyama and early Edo periods. He was the son of Kuroda Kanbei, Toyotomi Hideyoshi's chief strategist and adviser. His child-hood name was Shojumaru . In 1577, when Nagamasa was a small child, his father was tried and sentenced as a spy by Oda Nobunaga. Nagamasa was kidnapped and nearly killed as a hostage. With the help of Yamauchi Kazutoyo and his wife, Takenaka Hanbei ended up rescuing him. After Oda Nobunaga was killed in Honnō-ji incident of 1582, Nagamasa served Toyotomi Hideyoshi with his father and participated in the invasion of the Chūgoku region. Nagamasa also participated in the first Korean campaign , commanding the Third Division of 5000 men during the first invasion 1592-1593. In the second part of the campaign  he held command in The Army of the Right. He took part in the Battle of Sekigahara in the year 1600 serving under Tokugawa Ieyasu. His men killed Shima Sakon, securing victory for the Eastern army. As a reward for his service at Sekigahara, Tokugawa granted Nagamasa Chikuzen  - 520.000 koku - in exchange for his previous fief Nakatsu, Buzen.Later he participated in the Osaka Castle campaigns.
Question: How many years after Nagamasa took part in the first invasion did he take part in the Battle of Sekigahara?
Answer: 7