Sandline International had roots in the soil of Executive Outcomes, sharing relations with Buckingham's platoon of companies in Heritage Oil and Gas, Plaza 107 and the system of companies orbiting the EO diaspora. The company officially owning Sandline was Adson Holding and they were registered in the Virgin Islands.
The CEO was Lt. Col. Tim Spicer, a former SAS officer who recognized the potential of the private military sector and was in charge of projects that spanned throughout Africa as well as reaching into Papua New Guinea. Spicer would go on to begin Aegis Defence Services.
Sandline was an active PMC, engaging in direct conflicts, training troops for current conflicts, and closely related to mineral and oil extraction companies. Tim Spicer and the company gained notoreity in the nineties for two largely publicized events: their intervention in Sierra Leone and their role against the inhabitants of Bougainville, Papua New Guinea.
In Sierra Leone, they continued in the civil war where Executive Outcomes left off. However, the deal was put together by a shady embezzler, Rakesh Saxena, interests in DiamondWorks, members of the British government, and 35 tons of weapons from Bulgaria which eventually broke a British recognized international ban against Sierra Leone.
The incident, which became known as the Sandline Affair, was investigated by Parliament and was the second public scandal for the company. A year earlier, Spicer had been jailed in Papua New Guinea by an army revolt due to his role in aiding the government's agenda with the Rio Tinto mining operation that was polluting the island of Bougainville. This too led to investigations by the British government. 
Spicer left soon after, yet the company continued until April of 2004 when the closed shop and left a note on the door that somewhat sourly read:
- The general lack of governmental support for Private Military Companies willing to help end armed conflicts in places like Africa, in the absence of effective international intervention, is the reason for this decision. Without such support the ability of Sandline to make a positive difference in countries where there is widespread brutality and genocidal behaviour is materially diminished.
Sandline Denies Many Allegations
Sandline released a long list of corrections to a book released in 2000 by Pluto Press, Mercenaries: An African Security Dilemma edited by Abdel-Fatau Musah and J. 'Kayode Fayemi. The book traces the maze of relationships engulfing EO, Sandline, Buckingham, Mann, Grunberg and the rest. The corporate structure portrayed in the book is questioned in this response from Sandline.