  The ruthenium halide $\alpha$-RuCl$_{3}$ is a promising candidate for a
Kitaev spin liquid. However, the microscopic model describing
$\alpha$-RuCl$_{3}$ is still debated partly because of a lack of analogue
materials for $\alpha$-RuCl$_{3}$, which prevents tracking of electronic
properties as functions of controlled interaction parameters. Here, we report a
successful synthesis of RuBr$_{3}$. The material RuBr$_{3}$~possesses
BiI$_3$-type structure (space group: $R\overline{3}$) where Ru$^{3+}$ form an
ideal honeycomb lattice. Although RuBr$_{3}$ has a negative Weiss temperature,
it undergoes a zigzag antiferromagnetic transition at $T_\mathrm{N}=34$ K, as
does $\alpha$-RuCl$_{3}$. Our analyses indicate that the Kitaev and non-Kitaev
interactions can be modified in ruthenium trihalides by changing the ligand
sites, which provides a new platform for exploring Kitaev spin liquids.
