Doubling unconditionals are exemplified by the Spanish example Venga quien venga, estaré contento 'Whoever comes, I'll be happy' (lit. 'Comes who comes, I'll be happy'). This curious and little studied construction is attested in various forms in a number of Romance and Slavic languages.
In this paper, I provide a basic description of these constructions, focusing especially on Spanish, Czech, and Slovenian, and argue that they can be brought in line with analyses of run-of-the-mill unconditionals (of the English type) if one recognizes (1) that the wh-structure within the unconditional antecedent (quien venga 'who comes') is a free relative and (2) that the free relative is focused. The focused free relative introduces alternatives and thus gives rise to the denotation proposed by Rawlins (Nat Lang Semant 40(2):111-178, 2013) for English unconditionals.
In the last part of the paper, I hypothesize that at least some non-doubling unconditionals could in fact have a doubling underlying structure, which is disguised by relative sluicing-clausal ellipsis with a relative pronoun remnant.