In 1888, the Portuguese government instructed its representatives in Mozambique to make treaties of protection with the Yao chiefs southeast of Lake Nyasa and in the Shire Highlands. Two expeditions were organised, one under Antonio Cardoso, a former governor of Quelimane, set off in November 1888 for Lake Nyasa; the second expedition under Serpa Pinto (now governor of Mozambique) moved up the Shire valley. Between them, these two expeditions made over 20 treaties with chiefs in what is now Malawi. Serpa Pinto met Johnston in August 1889 east of the Ruo, when Johnston advised him not to cross the river into the Shire Highlands. Although Serpa Pinto had previously acted with caution, he crossed the Ruo to Chiromo, now in Malawi in September 1889.