From Kiamboni, the Pokomo split into two groups and fled further south following the coastal line. One group was led by Sango Vere and the second group was led by Hidavo Barisa. Sango is asserted to be the founder of the Buu clan which is today associated with the Lower Pokomo. Hidavo is asserted to be the founder of the Gwano clan which is today associated with the Upper Pokomo.This second dispersion by the Pokomo from Kiamboni had a lasting effect on their settlement pattern. The Hidavo group crossed the Dodori River, moved southwards before changing course in an easterly direction, until they crossed the Indian Ocean and settled on one of the islands off the coast. They called this island “Buwa”. The Pokomo remember it as an island sufficiently near the shore that people on the mainland could be seen while on the island.
The Sango Vere group crossed the Dodori River at its first bend and took refuge at Mundane. They called it nsii ya milima i.e. “the country of mountains”. It was an area full of hills and rivers. The area today is known as Mundane Ranges. It is situated to the north of Pate Island on the mainland. The Pokomo felt secure in this area. The rivers and mountains in the Mundane area would at least protect them from the marauding Somali warriors even though they did not like this hilly area. It was not conducive for permanent settlement. The Pokomo later vacated this area and moved further south.
Today, this movement is evidenced by the presence of a group of Pokomo known as Wapokomo wa Mgine or alternatively known as Wapokomo wa Mundini who are found atMokowe and other places along the road from Witu to Lamu, as far as Pate Island. “Mgine” is an inlet on the mainland opposite Pate Island while “Mundini” is a corruption of Mundane Ranges. These Pokomo have now intermarried extensively with the Swahili and Arabs of Lamu and the name Wapokomo wa Mgine/Mundini is used to differentiate them with the other settlers on the islands. From the Mundane area, the Pokomo group led by Sango Vere migrated through the Mgine inlet area, moving further south. They crossed the Indian Ocean and met the other Pokomo group led by Hidavo already settled at Buwa. They were fascinated by the number of women who were almost out-numbering the men. They, therefore, nicknamed Buwa Island, Kwa wayamu meaning “the country of our sisters-in-law”. This nick-name stuck and it gradually replaced Buwa as the name of the island. It was later shortened to Yamu, Amu and finally it became known as Lamu. The Coastal groups though, still call it Amu to date.
Due to the scarcity of agricultural land on the island of Buwa (now officially called Lamu), the first Pokomo group led by Hidavo moved to the neighbouring island of Manda. The Ndera clan of the Pokomo confirm that they had lived on Buwa Island (Lamu) before settling on Manda Island. Another Pokomo clan called Dzunza also retain memories of Manda Island as an island to which one could walk from the mainland at low tide. Mt. Hidavo in Lamu today signifies the presence of the Pokomo during this period. This hill was named after Hidavo Barisa, who had led one group of the Pokomo from Singwaya during the migration. The District Commissioner’s official house was built on this historic hill where it stands to date.
Another period of peaceful settlement was ushered in among the Pokomo. The Hidavo group settled at Manda Island while the Sango group settled at Lamu. Some of the Pokomo spread to the other smaller islands of Pate, Siu, Faza and Shakani. They cultivated crops on the mainland and came back to live on the islands for safety.
The long peaceful settlement on the islands was disrupted by more Somali raids towards the end of the 16th century. The Somali crossed the ocean using rafts. These were big floating logs tied together. They were armed with swords, spears, axes, bows and arrows. They attacked the Pokomo and other Bantu groups on the islands. There were many battles fought between the Bantu and the Somali. The most fierce one was Viha vya mwazi meaning “bloody war”. It was fought at Buwa i.e. Lamu Island. The Somali emerged victorious. The defeated Bantu were forced to flee the islands. They fled and gathered at a place on the mainland which they called Jiokoweni. This name means “save yourselves”. It is now the present day Mokowe.
In an attempt to flee from the invading Somali, the Bantu groups moved south towards Kipini. They made a big raft which they used to cross the River Tana. The Pokomo called the raft ntirikicha. According to their oral traditions, the Mbeere, Akamba, Digo and Taita were the first to cross the river using the raft. The Pokomo were left behind since they were nursing a pregnant woman who was about to give birth. Thus, the Giriama gave them the name mimba komu meaning “advanced pregnancy”. This was later changed to “Pokomo”. They recall that this incident occurred during the heavy rains. Before they were ready to cross, there was a continuous heavy down-pour which resulted in floods. The raft which was tied by the river side was washed away by the floods at night. By the time they crossed, most of the other Bantu groups had already scattered in different directions. Only the Giriama waited for them.
From Kipini, the Pokomo were still led by Sango Vere and Hidavo Barisa. They migrated without any clear direction. Finally, they grouped themselves at a place where there were many mpeketso trees. The mpeketso are big wild trees which bear edible fruits known as nsonsozi. The Pokomo named this place Mpeketsoni. This is the present day Mpeketoni. From here, the Pokomo moved to Moa near Nyangoro. This place is situated between the present-day Garsen and Witu. Moa was reserved for the Pokomo and Nyangoro for the Giriama who were always together during the migration. Till now, Nyangoro is mainly inhabited by the Giriama and are surrounded by the Pokomo. The Giriama later continued with their migration to Mwangea Hills near Malindi.
By the early 1800s, the Pokomo had settled in most of their present day areas along the River Tana from Kipini and Ozi and expanded to Laini, Shaufu (Oda), Semikaro, Ngao, Marembo, Salama, and Chara. The second Pokomo group under Hidavo Barisa settled along the River Tana from Mnazini to Wenje, Hola and Bura.
The River Tana was, and still remains, the life-line of the Pokomo. Around 1860, the River changed course near Marembo, thereby cutting off all the old Pokomo villages from the much needed waters of the Tana. The Pokomo named the old river tsana ndeya (long river) in order to differentiate it from the new river course. However, most of the water was swept into the new river bed. The old river bed finally dried up. As a result, old lakes which were depending on the old river also dried up after some time. The lakes which dried up were Lake Chamadho, Lake Dyange, Lake Mulanga, Lake Masewa and Lake Sagema. The Pokomo could no longer stay in such a dry area without the rivers and lakes they were dependent on. They migrated and left their old settlements. The land they left was called Buu ya kaye (Old Buu-land). It was so named because the people who were mainly affected by the change of the river course and the subsequent drying up of the lakes were the Buu clan.
The Buu clan that was affected by the change of the river course founded new settlements along the new river bed. They founded new villages like Mihaja, Ngambwa (now called Gamba), Chikovu, Mudzi wa Badani (literally meaning “the forest village”), Sambae and Kalawa, following the river downstream in that order. They tilled the land and prospered like never before. Chikovu expanded rapidly and became the capital of the Buu clan. Chikovu was only a few hours walk from Witu. The River flowed near these villages to Galana Duesa near Ngao towards the Indian Ocean.
In the 1880s, the River Tana changed its course again, cutting off the villages of Ngambwa, Mudzi wa Badani, Sambae, Kalawa and Chikovu, the capital of the Buu clan. The River started flowing from Mnazini direct to Garsen, Kibusu, Ngao, Golbanti, Laini, Semikaro, Chamwanamuma to Kau and Kipini. This has remained the main course of the River Tana.
The Pokomo who were affected by the river change were, once more, forced to migrate looking for more conducive places for settlement. They named the old river course Tsana ya Ngambwa meaning River Ngambwa. It was later corrupted to become known as Tsana ya Gamba (River Gamba). Most of the Buu clan of the Pokomo followed the new river and settled along the eastern bank at a place they aptly named “Ngao”, meaning shield. Ngao prospered to become the new capital of the Buu clan. Others settled around Garsen area.