Walter Reinhardt was one of those European soldiers about whom we have enough information. Born in 1720 at Salzburg, Austria, he came to India to seek career opportunities. Initially he lived at Pondicherry, a French colony, from where he moved to South India and joined the French army and changed his name to Somrus which later on became Sumro. He spent some time in Karnataka and then went to Bengal where he joined the East India Company.

Not satisfied with the service of the British, he wandered from one place to another, until he found a job with Sirajud Daula. After the battle of Plessey, in 1757, he was again rendered unemployed but when Mir Qasim became the new Nawab of Bengal he joined his service. In 1763, he was involved in the killing of some Englishmen in Bengal; the Company named him as its enemy.

After the battle of Buxar (1763) one of the clauses of the treaty was to hand him over to the Company. Learning this, he left the camp and arrived at Rohelkhand and joined Hafiz Rahmat Khan. He served at nearly 13 or 14 different places. Finally he was employed by the Mughal noble Najaf Khan. In his service he was awarded Sardhana as a jagir where he lived till his death. Reinhardt Indianised himself and lived like an Indian noble. He kept a harem and married many women. One of them was Begum Sumru who inherited his property and played an important role in the politics of her time.

Another important military adventurer was George Thomas. Unlike other adventurers, he played a different role in the history of India. He came to India either in 1780 or 1781. Up to 1790, he spent most of his time fighting for his employers. During this period he studied the political situation of India, and reached the conclusion that instead of fighting for others it would be better to carve his own independent state and fight for his own interest. In 1797, he attacked Haryana but the local population resisted fiercely. However, he defeated them and made Hansi his capital. He repaired the fort and built walls to defend the city.

After settling down, he increased his army to protect his city and issued new coins to declare his independence. The first thing which Thomas did was to award pension to his soldiers. Those soldiers who were wounded in the war, got cash for their treatment and the families of those who were killed received half of their salary. These military reforms changed the character of his army. After setting up his small kingdom in Haryana, he followed a policy of aggression against the neighbours; he continued to raid the cities of Rajputana and Punjab for plunder and also to keep his army busy in warfare.

Daulat Rao Sindhia, the Marhatta leader, and his French commander Perron became alarmed by Thomas' increasing power. Perron, who wanted to extend French influence in India, was eager to crush Thomas. Therefore, he attacked Haryana and defeated him in many battles. Finally Thomas surrendered and left Hansi in 1801. After wandering he finally reached Banaras; there he met Captain Franklin and dictated to him his memoirs. Living a long time in India he became Indian in his manners and customs. He fluently spoke Urdu and Persian. In 1892, he died at Bahrampur.

Among the European adventurers two Frenchmen became very famous. One was De Boigne and the second was Perron. De Boigne came to India in 1778 and joined the East India Company where he studied military strategy and technique. Later, he went to Lukhnow where he learnt Urdu and Persian. He left the city in search of work and got into the service of the Marhatta chief Madhoji Sindhia. He organised the army on modern lines. He was particular that the soldiers should get regular salary.

De Boigne's major achievement was structuring the army on a new model which was unknown to India. For example, following some of Thomas' reforms he made rules that wounded soldiers should get financial aid; those who were permanently disabled were awarded a piece of land. The families of those who were killed were financially supported. He kept an ambulance on the battlefield to take care of the wounded. In 1805, when he retired he had 400,000 pounds in his possession, He went to France along with his son Ali Bakhsh and daughter Banu.

His successor, Perron, became the Marhatta governor of the North Indian territories. The annual income of his province was 1,632,000 pounds. Mughal emperor Shah Alam was under his control. Perron's monthly salary was Rs15,000 per month; he had other sources of income as well. When he went back to France he had 1,600,000 pounds.

The period of European adventurers came to an end when in 1803 General Lack defeated Peron and occupied Delhi. As the East India Company became powerful, it undertook the defence of the Indian states which ended the demand for European soldiers.