Mahsud

The Mahsud is a Karlani Pashtun tribe inhabiting mostly the South Waziristan Agency in Khyber Pakhtunkhwa province of Pakistan.

The Maseeds  usually pronounce their name Māsīd. They are divided into three great clans or subtribes, namely Alizai, Bahlolzai, and Shamankhel.  Maseeds usually call these Drei Māsīd, meaning the "Three Maseeds". Each tribe has his own Khan.

History
The Maseeds and the Wazirs succeeded in defeating the Khattaks and pushed them northeastwards towards Bannu and Kohat. Eventually, the Mahsuds settled at the center of Waziristan, in the Makeen, Kaniguram and Lada area.

During the British colonial period, the Maseeds were invaded   by the British Empire, in 1925's Pink's War.

Recent history
The Maseed helped in  defeating the British invading troops and saved Afghanistan, they contributed a lot because Afghanistan was nearly in the hands of British.
John Ayde described the Maseeds:

They are poor but brave… and although turbulent and difficult to deal with, still have a great love of their country and cherish their independence, possessing qualities that we admire ourselves, and which deserve consideration and respect.

Maseed are very good marksmen and have the reputation of trustworthiness. Maseed is the most independent of all the tribes. Even their own maliks have a very limited control over them. However, Maseed have been increasingly integrated within Pakistani society since independence.
Sir Olaf Caroe in his book published just after partition of the British India about Mahsuds
They hold aloof, and are continually engaged in aggressive warfare against their Wazir cousins, at whose expense they have encroached to acquire new lands. And to those who know both tribes, they present a different appearance. Pass along a road which is being used by babirs, or caravans, of these tribes- men, and it is not so hard to distinguish one from the other, not by his dress, for that is much the same, but by something indefinable in his air and carriage. The nearest I can get to it is to liken the Mahsud to a wolf, the Wazir to a panther. Both are splendid creatures; the panther is slier, sleeker and has more grace, the wolf-pack is more purposeful, more united and more dangerous.

The Saintly Poet of the East (Dr. Allama Iqbal) has  also prayed for the dominant tribes of Waziristan
Sher Shah Suri has so well said:

The distinction of tribes is the cause of all ruin.

Waziris and Mahsuds are names dearest to heart;

Alas! They feel no pride in being Afghans.

The Muslims of the mountains are divided into thousand tribes,

And every tribe has its own idol.

The same sanctuary is filled with Lat and Manat;

May God grant you power to break them all.

                                                         Zarb-e-Kaleem (Iqbal)

Mulla Powindah died in 1913. It could be said that he was the crownless emperor of one of the most fearsome of the Pashtun Tribes, the Maseeds. Upon his death, his son Shah Fazal Din was given leadership and his son-in-law, Mulla Abdul Hakeem Kakar, was appointed his adviser. They have good relations with Amir Abdul Rahman Khan, the Amir of Afghanistan.

In 1925, the Royal Air Force successfully put down a Maseed rebellion by strafing the tribes' mountain strongholds.  The action, which came to be known as Pink's War led to the tribal leaders seeking peace terms.

Lashkar invasion of Kashmir

Mehsud Sub-tribes 
Like other Pashtun tribes, the Mehsud tribe also has its own individual subtribes and clans:
 Shaman Khel
 Alizai
 Bahlolzai

Notable Mahsuds
 
 
 Abdullah Mehsud
 Baitullah Mehsud
 Hakimullah Mehsud

See also
Pashtun culture#Mahsud Attan (dance)
Pashtun Tahafuz Movement

References

External links
 Waziristan and Mughal empire
 Nehru in Waziristan
 Sketch map of Waziristan
 Lawrence of Arabia in Waziristan

Karlani Pashtun tribes