Like all his ancestors, Ferdinand Joseph was in the service of the House of Habsburg. He received the court offices (Hofamt) of Oberst-Erblandmundschenk in the Duchy of Carinthia and hereditary land-Jägermeister in the Duchy of Styria and later was appointed Kämmerer of Emperor Leopold I and member of the Privy Council.
An important task of Ferdinand Joseph took place in December 1666 on occasion of the marriage of the Emperor with his niece Margaret Theresa, Infanta of Spain and sister of the last King of the Habsburg branch, Charles II. Leopold I appointed him in 1667 Obersthofmeister of the then 15-year-old Empress; this was a great honor, but at the same time was not an easy task: the increasingly anti-Spanish sentiment in the Viennese court because of the inaccessibility of Margaret's entourage, and the pressure under which the Empress was after 6 years of marriage in which she gave birth to 4 children (of which only one daughter survived) and had several miscarriages, damaging her health. Ferdinand Joseph became the Empress' confidant and comforted her, and had to defend her against opposing courtiers who expressed their hope that the ailing Margaret soon die in order that the Emperor could contract a new marriage which could provided him with the long-awaited heir. Finally, the Empress died on 12 March 1673, aged 21. A few months later (15 October), Leopold I married again with his cousin Archduchess Claudia Felicitas of Austria, but Ferdinand Joseph remained in his post of Obersthofmeister for the new Empress.
Since 1668, Ferdinand Joseph was a member of the Order of the Golden Fleece as the Knight 466 since his foundation. In 1682 Emperor Leopold I appointed him his Obersthofmeister and became part of the secret Konferenzminister, thus was included in the selected group of not more than 2,000 persons who effectively ruled the Holy Roman Empire. He was able to exert a not inconsiderable influence on government policy; this was because as the Imperial Obersthofmeister he usually had a chair in both the Privy Council and with the Konferenzminister. While many member of the Privy Council are primarily concerned with questions of administration, taxation, privileges, etc., the Konferenzminister are a secret committee created by Leopold I, which consisted of a few (between 4 and 12) members. They are the most important foreign policy advisory body, as they addressed issued for the Imperial House and are responsible for the policy in both the Holy Roman Empire and the Habsburg hereditary lands. At the same time, Ferdinand Joseph as a member of this selected group, reported the outcomes and decisions directly to the Emperor.
However, this wasn't an easy task. The current government policy was subjected to the constant intrigues of court rival parties and, as the most devoutly Catholic court in Europe, the spiritual advice was also fundamental. In addition, the tense international situation caused problems to him: just a year after his appointment in July 1683 took place the second Turkish siege of Vienna by Kara Mustafa Pasha; only thanks to the help of the Polish King Jan III Sobieski and Pope Innocent XI the Imperial capital was saved. In the Great Turkish War, the city of Belgrade was sieged and captured in 1688 and all Hungary was freed by the decisive victory of Prince Eugene of Savoy in the Battle of Zenta, who was the base for the Austrian rise as a major power. On the political level, the resistance of the Hungarian nobility against the Habsburg rule was partially ended with the consent for the coronation of Archduke Joseph, Leopold I's eldest son, as King of Hungary in 1687. In the west, however, King Louis XIV of France was a successful threat for the Empire: in 1683 he capture the imperial city of Strasbourg and in 1688 he entered in the Rhineland, after having devastate the Rhenish Palatinate. The war against France (called the Nine Years' War) began, but had little success. By the Peace of Ryswick in 1697 the Spanish Netherlands where ceded to France.
Seat and vote in the Reichstag
An important personal event for Ferdinand Joseph was the execution of a pending question for decades: the confirmation of the princely title for the Dietrichstein family. Already in 1624 his great-uncle Franz Seraph (Cardinal since 1599 and Prince-Bishop and Duke of Olomouc since 1600) was elevated to the title of Imperial Prince. His father Maximilian not only received the title in 1629 but also at the Imperial Diet of Regensburg in 1654 obtained the authorization of a seat and vote. This, however, was only provisional, and the confirmation was subject to the condition of the acquisition of a direct imperial territory. Subsequently, however, due to the lack of compliance with the requirement, the princes protested on the Imperial Diet, so Maximilian was virtually excluded from a direct participation. Ferdinand Joseph finally succeeded with the requirement in 1678 with the acquisition of the imperial district of Tarasp in Graubünden, granted by Emperor Leopold I in recognition of his services (incidentally, Tarasp was the last Austrian enclave in Switzerland, and the first who was mediatizated in 1803 and annexed to the Helvetic Republic). The legal issue was finally regulated in the Perpetual Diet of Regensburg on 29 May 1686. Ferdinand Joseph was appointed Austrian ambassador on 4 October 1686 and (this time for good) he received a vote and a seat in the Imperial princely college, between the Princes of Salm and Nassau-Hadamar.
Rights of Minting coins
Ferdinand Joseph exercised his rights to mint coins at least twice. Are preserved imprints of thalers from the year 1695 and ducats from the year 1696. As a result, there are also contemporary representations of the prince, because on both coins on the front of his chest image with great wig, lace ruff and the Golden Fleece, with the inscription "Ferd. S. R. I. Princeps a Dietrichstein" (Ferdinand Imperial Prince of Dietrichstein) and on the back were adorned with the chain of the Order of the Golden Fleece and the Dietrichstein coat of arms with the inscription "In Nicolspurg et dominus in Trasp" (in Nikolsburg and Lord of Trasp) can be seen.
Expansion of possessions
Ferdinand Joseph was one of the wealthiest landowners in Austria, but he knew that his fortune -and thus the power base of his house- came from multiplying his lands; in consequence, in 1660 he bought from the heirs of the Count Tilly the Lordship of Reichersdorf, in 1675 the district of Franzhausen and later Nussdorf an der Traisen, all districts in Lower Austria. In 1678 he paid the mortgage of the Lordship of Tarasp and the Emperor granted him (as a special grace) the full sovereignty over this land, and in this way Tarasp obtained the imperial immediacy. Another economically significant event was that his distant cousin (member of the Hollenburg line) Gundakar of Dietrichstein, imperial minister and ambassador, since 1656 Imperial Count and since 1684 Imperial Prince, instituted a Fideikommiss for him, which Ferdinand Joseph inherited in 1690 after Gundakar's death. He also acquired the domains of Libochovice, Budyně nad Ohří, Pátek, Nepomyšl and Vlachovo Březí, all in the today Czech Republic.
Ferdinand Jiseph also used his wealth for social and charitable purposes. His father, as universal heir in 1654 of the Countess Johanna Franziska Magnis, established in her name a school dedicated to the Virgin Mary in Brno. However, the funds originally dedicated for this objective are 60,000 guilders (extracted from the district of Medlanko and Brno) proved to be insufficients, Ferdinand Joseph therefore transferred his rights over the Lordship of Mährisch-Neustadt for the foundation, which finally was completed. Thus, 12 orphaned girls between 12 and 20 years, of which 4 belonged to the Herrenstand, 4 to the Ritterstand and 4 to the Bürgertum received an education and a dowry for their marriages. The prince even established hospitals in Nikolsburg and Libochovice.