He was born into a Transdanubian bourgeois family in Szombathely on 16 August 1852,[1] as the third child of József Márkus Sr. (1822–1873), who worked as a miller at the local gristmill, owned by Prince Fülöp Batthyány.

Decades later Ferenc Harrer pointedly noted in his memoir (Egy magyar polgár élete, "The Life of a Hungarian Bourgeois") that Márkus could thank his professional career merely because of his family relationships.

He was an author of the progressive Reform daily newspaper, before joining as a columnist responsible for Budapest affairs to the Nemzeti Hírlap, edited by István Toldy, in 1873.

He played a major role in the establishment of the Elevator House and several other warehouses in the early 1880s, as a result he was awarded the Crowned Gold Cross of Merit by King Francis Joseph in 1884.

He was elected a councillor to the Municipal Local Board of the General Assembly of Budapest five years later, on 1 April 1890, he was the youngest person who held the dignity during that time.

Shortly thereafter Márkus led a 25-member delegation to Turin, where freedom fighter and statesman Lajos Kossuth died after spending his last years in exile on 20 March 1894.

[3] In May 1895, along with Jenő Rákosi and Count József Majláth, he was a founding member of the National Association (Hungarian: Országos Nemzeti Szövetség), which set the objective of improve social conditions for workers, and ethnic reconciliation to counteract socialist and nationalist conflicts and protests countrywide.

Throughout the 1896 millennium celebrations, lasted from 2 May to 31 October, which commemorated the anniversary of the Hungarian conquest of the Carpathian Basin, Márkus personally managed the program of events on behalf of the city administration and maintained contact with the Bánffy government.

He considered the relatively young Márkus as his trusted successor, despite the fact that Gerlóczy held the office of First Deputy Mayor since the unification of the city in 1873.

According to the city unification law (Statute XXXVI of 1872), the General Assembly had to elect the next Lord Mayor among the three candidates nominated by countersignature of Francis Joseph after consultations with the Ministry of Interior.

Harrer published an urban legend in his memoir which suggested that Márkus was actually nominated by Wilhelm II, German Emperor to the position, when visited the millennium celebrations in 1896.

[6] As Lord Mayor, Márkus represented his predecessor's role perception, maintaining a broker relationship between the national government and the city administration.

In comparison to Ráth, Márkus tried to enforce the office's audit function by adopting a more ambitious approach, but that did not lead to conflict regarding Budapest's autonomy.

[9] According to the contemporary press, the general public in Budapest considered Márkus' election as waste of an agile and energetic career, since the position of Lord Mayor was associated with limitied and more passive powers.

A journalist of the Pesti Hírlap argued that the Lord Mayor showed his forceful behavior only against employees, which vanished during negotiations with equal partners.

He participated in the work of several social organizations; he served as a member of the Directorate of the Railway Society of Budapest and functioned as Chairperson of the Home of Private Officials.

Accordingly, the General Assembly decided not to provide the collected taxes to the central budget, and also authorized Mayor János Halmos to deny to execute the government decrees.

[11] On behalf of the General Assembly, he was farewelled by Géza Polónyi (a member of the Second Wekerle cabinet one month later), who said Márkus "remained a constitutionalist and patriot even in difficult times, who chose the respect for constitution against the high and dignified office in a risky situation."

When Francis Joseph intended to appoint a royal commissioner (Budapest Police Chief Béla Rudnay) to lead the resistant city administration, Márkus argued that the monarch should also respect the Hungarian laws and constitutionalism.

[13] He said Márkus' "operation was permeated by a Hungarian democratic patriotic sentiment, a humanist liberal thought, and a versatile knowledge, which covered every field of urban management [...]".