The International Barley Genome Sequencing Consortium presents an integrated and ordered physical, genetic, and functional sequence resource for the barley genome. Barley, a globally important crop with a large haploid genome of 5.1 gigabases (Gb), is a diploid species. The consortium developed a physical map of 4.98 Gb, with over 3.90 Gb anchored to a high-resolution genetic map. Deep whole-genome shotgun assembly, complementary DNA, and RNA sequence data support 79,379 transcript clusters, including 26,159 'high-confidence' genes with homology support from other plant genomes. The data reveal abundant alternative splicing, premature termination codons, and novel transcriptionally active regions, suggesting post-transcriptional processing as an important regulatory layer. Survey sequences from diverse accessions show extensive single-nucleotide variation. The resource provides a platform for genome-assisted research and crop improvement. Barley, derived from its wild progenitor, is among the world's earliest domesticated crops and is widely used for animal feed, malting, and food products. It is adapted to diverse environments and has high dietary fiber content, making it a functional food. The availability of a reference genome sequence is crucial for advancing barley research and breeding. The consortium's work includes constructing a genome-wide physical map, integrating shotgun sequence information, and generating whole-genome shotgun sequence data. The physical map covers 9,265 BAC contigs with an estimated N50 contig size of 904 kilobases, representing more than 95% of the barley genome. The genetic map was built using a single-nucleotide variation (SNV) map and high-density genetic marker maps. The consortium also annotated the genome with deep-coverage RNA-derived data, including full-length cDNA and RNA-seq. The resulting gene space provides insights into gene distribution, repetitive DNA, and genetic characteristics such as recombination frequency, gene expression, and genetic variation. The study highlights the importance of centromeric and peri-centromeric regions in gene expression and genetic diversity. The consortium's work provides a comprehensive resource for genetic research and breeding, facilitating trait isolation, understanding natural genetic diversity, and investigating the unique biology and evolution of barley.The International Barley Genome Sequencing Consortium presents an integrated and ordered physical, genetic, and functional sequence resource for the barley genome. Barley, a globally important crop with a large haploid genome of 5.1 gigabases (Gb), is a diploid species. The consortium developed a physical map of 4.98 Gb, with over 3.90 Gb anchored to a high-resolution genetic map. Deep whole-genome shotgun assembly, complementary DNA, and RNA sequence data support 79,379 transcript clusters, including 26,159 'high-confidence' genes with homology support from other plant genomes. The data reveal abundant alternative splicing, premature termination codons, and novel transcriptionally active regions, suggesting post-transcriptional processing as an important regulatory layer. Survey sequences from diverse accessions show extensive single-nucleotide variation. The resource provides a platform for genome-assisted research and crop improvement. Barley, derived from its wild progenitor, is among the world's earliest domesticated crops and is widely used for animal feed, malting, and food products. It is adapted to diverse environments and has high dietary fiber content, making it a functional food. The availability of a reference genome sequence is crucial for advancing barley research and breeding. The consortium's work includes constructing a genome-wide physical map, integrating shotgun sequence information, and generating whole-genome shotgun sequence data. The physical map covers 9,265 BAC contigs with an estimated N50 contig size of 904 kilobases, representing more than 95% of the barley genome. The genetic map was built using a single-nucleotide variation (SNV) map and high-density genetic marker maps. The consortium also annotated the genome with deep-coverage RNA-derived data, including full-length cDNA and RNA-seq. The resulting gene space provides insights into gene distribution, repetitive DNA, and genetic characteristics such as recombination frequency, gene expression, and genetic variation. The study highlights the importance of centromeric and peri-centromeric regions in gene expression and genetic diversity. The consortium's work provides a comprehensive resource for genetic research and breeding, facilitating trait isolation, understanding natural genetic diversity, and investigating the unique biology and evolution of barley.