Wertheimer soon gained the confidence of Emperor Leopold I, who presented a portrait of himself to Wertheimer and his son Wolf, and on 15 December 1701 followed this gift with another of 1,000 ducats for the financier's success in obtaining for the daughter of the King of Poland a dowry of 1,000,000 florins from her father upon her marriage to Leopold's brother-in-law Duke Charles Philip.

In the Spanish War of Succession, Wertheimer united with Samuel Oppenheimer to procure the money necessary for the equipment of the Imperial Army and for the supply of provisions.

After Oppenheimer's failure, and his sudden death in 1703, Wertheimer maintained the credit of the state and found new sources of income.

On 29 August 1703 the emperor appointed him court factor, and extended for twenty years his privileges of free religious worship, denizenship, and immunity from taxation.

The title of "Landesrabbiner", which the Jews of Hungary had bestowed on Wertheimer, was made effective by Charles VI (26 August 1711).

He possessed many of the palaces and gardens in Vienna, and numerous estates and houses in Germany, e.g., in Frankfurt am Main, Worms, and other cities.

In a manuscript volume he left a number of derashot that he had delivered in the private synagogue in his house; these show considerable Talmudic erudition.

Moses Meïr Perls, for many years Wertheimer's secretary and almoner, mentions him in his "Megillat Sefer" (1709) as "a rabbi of great congregations in Israel."

In some works Wertheimer is called "rabbi of Prague and Bohemia"; but he did not accept this title, as may be seen in an edition of Alfasi (Frankfurt-am-Main, 1699–1700).

When Eisenmenger's Entdecktes Judenthum appeared in Frankfurt in 1700, Wertheimer addressed to Emperor Leopold a petition in which he warned of the grave dangers which it would bring upon the Jews.

Having invested a large part of his wealth in loans to the Bavarian government, the stipulated terms of repayment were not kept, and bankruptcy stared him in the face.

For a time he was able to pay only half of the interest on the 150,000 florins which Samson Wertheimer had donated to charity, and of which Wolf was trustee.

Samson's second son, Löb, married a daughter of Issachar ha-Levi Bermann of Halberstadt, a relative of Leffman Behrens, court Jew of Hanover; thus the three great "shetadlanin" were closely connected.