He was a prominent Jewish leader in Vienna in the interwar period and in the nascent State of Israel, where he established his court in Tel Aviv.

He was engaged at the age of 11[6] to Bluma Raizel, daughter of Rabbi Yitzhak Meir Heschel of Kopychyntsi, the Kopshitzer Rebbe; they married when he was 18.

[7] Upon his father's death in 1907, he and his brothers all became Rebbes, making their courts and conducting their tishen in different halls in the great Sadigura synagogue.

Rabbi Avrohom Yaakov established his court in Vienna and led the Sadigura Hasidim from that city for the next 24 years.

His Hasidim obtained a visa for him that year and for many months after he arrived in Tel Aviv, he swept the streets around his house early each morning.

[16] Like other Rebbes of the Ruzhiner dynasty, he was humble and modest on the outside, while on the inside he burned with love of God and fierce allegiance to Torah and mitzvahs.

[2] His divrei Torah were collected in a volume under the name Hebrew: אביר יעקב (Avir Yaakov).

He did agree to sit in his brother's place at tishen held on Jewish holidays and on the yahrtzeits of his Ruzhiner and Sadigura ancestors.