Task: Question Generation
Input (English): Passage: After the fall of Pegu in December 1599, Lower Burma was in utter chaos, and politically fragmented among Toungoo, Prome, Arakanese/Portuguese Syriam and Siamese Martaban. In Upper Burma, however, Nyaungyan, viceroy of Ava, had been quietly consolidating his holdings since 1597. Though nominally loyal to Nanda, Nyaungyan provided no support to his overlord. In October 1599, just as Toungoo and Arakanese were laying siege on Pegu, Nyaungyan sent a force to reclaim Mohnyin, Mogaung, and Bhamo. After Pegu fell, Nyaungyan declared himself king on 25 February 1600. Nyaungyan then systematically reacquired nearer Shan states. He captured Nyaungshwe in February 1601, and the large strategic Shan state of Mone in July 1603, bringing his realm to the border of Siamese Lan Na. In response, Naresuan of Siam marched in early 1605 to attack Mone but died at the border in April after which Siam ceased to be a military concern to Burma. In early 1606, his 7,000-strong forces took Theinni, Thibaw and Momeik but the king died during the campaign on 3 March 1606.
Output (English): Nyaungyan declared himself king how many years after the fall of pegu?