Guryev knew how to please him, even to master him, and for more than three years traveled with him in Europe.Following this, his marriage in 1785 to Countess Praskovyya Nikolaevna Saltykova (1764-1830) introduced him into the circle of the Petersburg aristocracy and brought him closer to the Imperial House.

After the accession of Alexander I and primarily thanks to the assistance of his "young friends" on August 26, 1801, Guryev was appointed manager of the Cabinet of His Imperial Majesty, and on September 8, 1802, he became a comrade (or, in other words, deputy) Minister of Finance, of already old and permanent ailing Count Alexei Vasiliev.

In February 1804, Dmitry Guryev was granted the position of Actual Privy Councillor, and on July 9, 1806, he was appointed to the post of Minister of Appanages, which he held until the very end of his life.

During this rather turbulent period, when the former "young friends" of the Grand Duke one after another left from the political life of Russia, Mikhail Speransky, the future State Secretary, occupied an increasingly strong position at the throne.

In view of the difficult economic situation in the country, in November 1809, Emperor Alexander I instructed Speransky to prepare an urgent program for overcoming the financial crisis.

To prepare the project, a special committee was formed, in the discussion of which Guryev also took an active part, in recent years having become very close to Mikhail Speransky.

A pragmatist and subtle courtier, Dmitry Guryev used all his intellect and Speransky's growing influence on the emperor in the struggle for the coveted chair of finance minister and by 1810, he finally managed to "overthrow" his predecessor, Fyodor Golubtsov.

Outwardly demonstrating his full support for the new ministerial system of Mikhail Speransky, aimed primarily at strengthening the vertical of power, on January 1, 1810, Dmitry Guryev, under his patronage, was appointed Minister of Finance and at the same time a member of the new reformed State Council.

However, despite such a reputation, Alexander I entrusted him with the most important task at that time to stabilize the country's financial situation, which had been pretty shaken by the entire previous trade, industrial and customs policy.

According to the first point of the plan, in 1810, metal circulation was restored and part of the bank notes was withdrawn to increase their value, a number of internal loans were undertaken, which stabilized the state budget.

In 1816, Dmitry Guryev's most resigned note, entitled "On the Organization of the Supreme Governmental Places in Russia", in which he directly proposed strengthening the power of the ministers and giving them legislative functions, also belongs to him.

And yet, at the behest of Alexander I, Dmitry Guryev, who already had a reputation as a liberal, in 1818–1819, headed (as Minister of Appanages) the work of the Secret Committee to prepare a draft peasant reform.

[9][10] By the beginning of the 1820s, a turning point was clearly outlined in the political worldview of Alexander I, when, on the basis of the collapse of foreign policy liberalism, he became disillusioned with the program of internal reforms in Russia.

His leadership of the financial department fell on the hardest time of the Patriotic War of 1812, and then during the elimination of its socio-economic consequences and the second renaissance of state liberalism, which found expression primarily in attempts to resolve the peasant question.

The breakdown and decline of Guryev's ministerial career, outwardly associated with his disagreements, and then a break with the all–powerful Alexey Arakcheev, in fact, clearly demonstrated the strengthening of protective tendencies in the government's policy and an increasingly distrustful attitude towards the problem of reforms.

[12] The arrogant nobility, however, could not forgive Guryev of a comparatively low origin, for what he had in the world... ... all the habits of the greatest aristocrat, although his father, almost from a taxable state, was the steward of one rich, but not a noble and provincial landowner; but he himself married Countess Saltykova, an elderly girl, from whose hand, despite her great fortune, everyone ran for a long time.The proper name of the Minister of Finance and Appanages, Dmitry Guryev, outlived his political career for a long time, became a household name and firmly entered the everyday life of the Russian language.

He gave dinners to his noble new relatives, and only to them; his house began to be revered as one of the best, and he himself was among the first patricians of Petropolis.From 1785, he was married to Countess Praskovya Saltykova (1764 – 10 May 1830),[13] daughter of the Life Guards Lieutenant Count Nikolai Saltykov (1743–1800) and his wife, Princess Anna Gagarina (1742 – 21 April 1820).

At one time, the house of Countess Guryeva was in the evenings a favorite gathering place for the Saint Petersburg elite society and the entire diplomatic corps.