By the 2nd century BC Saba' was declining gradually and its southern neighbor Himyar was able to settle many nomadic tribes that were allied to Himyar and create a stronger Himyarite nation in the lowlands. Eventually Saba' was incorporated into Himyar and resistance was reduced to the Kahlan tribes who were overpowered by Himyar and forced out of Highlands in Yemen. Most Of Kahlan remained in the Yemeni desert region around Marib until the destruction of the Dam in the 3rd century AD. this forced the Kahlani tribes to emigrate northwards through Arabia. They reaching as far as Mesopotamia and Syria prior to the 7th Century Arab conquests under Islam. After the Arab conquests, the Kahlani Arabs, among other Qahtani and Adnani tribes, reached all the way to the far edges of the Umayyad Empire.
Imran bin Amr and the bulk of the tribe went to Oman where they established the Azdi presence in Eastern Arabia and later invaded Karman and Shiraz in Southern Persia. Another branch headed west back to Yemen and a group went further West all the way to Tihama on the Red Sea. This branch will become known as Azd Uman after Islam.
Thalabah bin Amr left his tribe Al-Azd for Hijaz and lived between Thalabiyah and Dhi Qar. When he gained strength, he headed for Yathrib where he stayed. Of his seed are the great Aws and Khazraj, sons of Haritha bin Thalabah. Those will be the Muslim Ansar and will produce the last Arab Dynasty in Spain (the Nasrids).
Under the leadership of Malik bin Uday bin Al-Harith bin Murr bin Add bin Zayed bin Yashjub bin Uraieb bin Zayed. They spread to the North mainly in Southern and Western Mesopotamia, Rafah, Golan, Hauran and they were the first Southern Arabs to settle Northern Egypt where they were later joined with the Sicasik, Banu Judham and the Ghassanids. The Lakhmids produced The Abadi, Ubadi and Banu Bahr dynasties in Spain. Other notable Lakhmid is the late Arab leader Gamal Abdul Nasser from the Bani Mur of Banu Lakhm.
Led by Usma bin Luai in their massive exodus out of Yemen (115 BC), the Tayy invaded the mountains of Ajaa and Salma from Banu Assad and Banu Tamim in northern Arabia. The Tayy became camel herders and horse breeders and lived a nomadic lifestyle in northern Nejd for centuries. Because of their strength and blood relations with the Yemenite dynasties that came to rule Syria (Ghassan) and Iraq (the Lakhmids), they expanded north into Iraq all the way to the capital at the time al-Hirah. Tayy later changed their name to Shammar, renaming the mountains of Ajaa and Salma to Jabal Shammar (Shammar's Mountain).
The Kindah dwelt in the Bahrain but were expelled to East Yemen a group of them moved to Nejd where they instituted a powerful government that was a vassal kingdom for Himyar. They gradually declined After the fall of Himyar in 525 AD. The Kindites towns fell under constant bedouins raids from Nejd that eventually destroyed the Kindites and they were absorbed into the Nejdi tribal federations.
Largely settled in Wadi Do'an east of Hadramout and did not play a major rule in the Kendite kingdom. they had long lasting battles with the native tribes of hadramout.
Alongside Banu Al-Sokon, they fairly ruled Hadramout.
The Sakasic were a Himyarite tribe that settled Northern Egypt around 3rd century AD. They settled the ancient town of Bubastis in Egypt giving it its modern name Zaqaziq after the name of their Yemeni Tribe Sakasic. Also its one of Egypt provinces.