Some scholars consider the Janer family past an illustration of social history in Catalonia, its rise and decline demonstrating patterns of change within the local ruling strata.

[1] Erasmo's paternal grandfather Domingo Janer Sunyer (1762-1807) was son to a provincial doctor[2] and commenced his career as a petty merchant from Esparreguera;[3] rising to prosperity, he was ennobled in 1795.

[7] Himself representative of a new strata of commerce and industry tycoons which started to surpass landed aristocracy and old urban bourgeoisie,[8] in the mid-19th century Janer Gónima brought the family to business and political climax.

[23] José Erasmo and Dolores had 7 children, though only two of them married: the second oldest son[24] and the family heir Ignacio Janer Milá de la Roca became a locally known historian and writer,[25] while Mercedes wed a Carlist politician Dalmacio Iglesias.

[58] According to one source he joined a small team, led by Tírso de Olazábal and busy procuring arms for the Carlist troops;[59] it is likely that taking advantage of his wealth, Janer contributed financially.

A number of sources point vaguely to the late 1870s when claiming that together with Milá de la Roca and Llauder Janer was among co-founders of a new Carlist daily which would remain in print for the following 60 years, El Correo Catalan.

[70] In the 1880s Carlism did not exist as organized structures present in the Spanish public life; the movement languished as a set of loose quasi-political initiatives flavored with Traditionalist spirit and intransigent religiosity.

[76] Following the Integrist secession Carlism abandoned its quasi-political format of the 1880s and assumed a decisively more active political stance; the nationwide structures started to emerge, initially styled as committees celebrating 1,400 years since the Conversion of Recaredo.

Though Carlist candidates started to take part in electoral campaigns and under the new nationwide leadership of Marqués de Cerralbo the movement took shape of an organized modern political party, there is little information on Janer's public activity in the early 1890s.

[79] His popular initiatives stuck to the pilgrimage format, e.g. when organizing workers' romería to Rome in 1894[80] or signing homage letter to the papal nuncio; the document protested the governmental secularization policy.

He was barely mentioned when new party círculos in the region were being opened, typically noted when presiding over official banquets[83] or entertaining royal Carlist figures, e.g. the second wife of the claimant Berthe do Rohan, who visited Barcelona in 1896.

[84] Though historiographic studies either on Catalan[85] or nationwide Carlism[86] of the 1890s barely mention his name, de Cerralbo was apparently satisfied with Janer's contribution to the cause; Jefe Delegado addressed him with effusive letters of gratitude and thanked him for electoral efforts;[87] press of the era provides little evidence of such support.

Since 1898 due to his poor health Llauder's leadership became largely theoretical, while the movement was plagued by personal squabbles, emerging social radicalism, urban pistolerismo, Catalanist sympathies and insurrectional currents.

[92] Janer's tenure fell on a period when Catalan Carlism was challenged by massive social and political change, the decade which shifted the region's centre of gravity from rural traditional hinterland to the coastal strip, dominated by new urban classes.

[105] However, the dissent was mounting, fuelled also by personal squabbles and issues related to tactical alliances with the Alfonsists; to enforce discipline at times Janer opted for dissolution of municipal[106] or even provincial party jefaturas.

[110] Contemporary press noted that Janer was a great Christian, grand citizen and by all means an extraordinary person, but neither a good leader nor an impressive politician, tending to inactivity and with scarce faith in the cause.